It takes place a month and a half, or just a little longer, after the end of my "Once Upon A Handplate" fanfic. If you haven't read it, you'll be confused about who Patty is, or about some mentioned characters or events. The Gaster here is the Zarla's one. You may think it's OOC for him, but it's actually a consequence of his long emotional journey throughout my other fic. Anyway… I tried to write it not too detailed, since the main focus of this story (like my other ones) are feelings. It's not that much about the act itself as it is about what it means to the characters. I mixed sensuality and sweetness. So… enjoy?

Disclaimer: I don't own Gaster, he belongs to Toby Fox (and Zarla). But I do own Patty.

Gaster was a man who'd always educate himself through books, those having been the main source of knowledge and inspiration for his science projects. It wasn't abnormal for a scientist. However, never had he thought that a book would inspire him in his romantic life. It all started an evening when Gaster and Patty were discussing their likes and dislikes, more specifically their litterature tastes. Gaster had asked Patty what her favourite book was, who easily gave him as response the title of a romance novel. It didn't surprise the skeleton a single bit. But then, his girlfriend suggested him to read the said book and then tell what he thought about it. Patty was convinced that he'd like it too, despite that Gaster claimed he wasn't into romance novels. Gaster accepted to do this for her. Here he was now, lying on the couch and reading that book. It was true that he wasn't that much into romance novels, since those were in his opinion unrealistic, filled with the same silly codes, had a mushy resolution, and the conflicts being unnecessary dramatic. Not to mention the main heroes usually taking not the cleverest decisions. But Gaster had read a few of those in his life out of mere academic curiosity. Every single time, he'd read it with a form of amusement and critique, but not being that much invested in the story itself. So when Patty handed him the novel, Gaster expected the reading experience to be no different from the other times. Gaster had started to read it with a cynical and detached attitude… which didn't last for very long. This time, the story kind of captured Gaster and his interest. But there was a reason to this. In fact, the two protagonists of the book reminded Gaster very much of himself and Patty. The hero was a rather brooding, distant, and somewhat intellectual, while the heroine was all joyful, imaginative, and very social. As Gaster progressed in his reading, he couldn't help but imagine himself and his girlfriend in the places of the protagonists. And because of this, Gaster started to quite enjoy the story in the spite of himself. But he couldn't admit it, not totally. Patty regularily asked him with all the enthousiasm in the world:
"So? Which part did you stop at? Do you like it so far?"
But Gaster would always just shrug and say a very unpersonal:
"It's not mediocre, I guess."
Despite Patty's pleas, Gaster wouldn't develop his view on the book. Patty had a feeling Gaster wasn't being totally honest wih her, but to her disappointement, he'd always have that indifferent attitude whenever she asked about the novel. As for Gaster, he'd secretely wait for the evening when he could project himself and Patty into the story. His mind was no longer seeing the protagonists described in the book, but it would always replace them by him and his girfriend. Gaster couldn't help it, it was happening on its own. At first, he was mentally scolding himself for this foolish attitude, but then he figured he didn't mind it that much. In a way, it was a good entertainement. Not that he'd ever tell this Patty.
Gaster was lying all relaxed on the couch, covered by a thin quilt, with a cup of golden flower tea at the coffee table. The skeleton noted that he'd already read about two thirds of the book. Some part of him was a bit disappointed he'd reach the end soon. Another part of him wondered what he'd tell Patty once he finished the book. He knew he couldn't get away with the basic "I didn't hate it." His girlfriend would want him to elaborate his opinion. But how could he tell her that he loved to imagine themselves in the shoes of the characters? What would she think of him? Gaster sighed, hoping he'd come up with the right words to say, as he turned a page. It was then that things took an unexpected turn. Very soon, as his eye went from line to line, Gaster's face went pale. This book had a lovemaking scene. Gaster felt sweat on his skull. It wasn't the first time he was reading an erotic scene, since some of the novels he's read in the past had those. Not to mention all the M-rated stories written by Alphys that she accidently sent to him. But he'd always read those without blinking an eye, such things being nothing more than a curious, yet alien, matter to him. This time however… Gaster felt his cheekbones heat up; he never thought he could blush this hard. As he felt the beating of his SOUL quicken, Gaster grabbed his cup and drank several nervous gulps of the lukewarm tea. Gaster then tried to mentally chase away the image of himself and Patty, hoping this would detach it from the scene, but it didn't work. How were the two protagonists even described to look like? His mind was too used to see his girfriend and him instead. And the anatomy dismatch barely altered Gaster's inner vision. Gaster's mind told to skip that part, but the curiosity of the situation he and Patty could be in was too strong. His eyes just couldn't stop reading the lines. As soon as the lovemaking scene came to its end, Gaster closed the book at once, and for a moment, he was like frozen. His cheekbones were still as red as tomatoes and, he noted, his SOUL felt as though it was burning. "I think I need a cold shower." - he thought. He stood up from the couch and went upstairs in the direction of the bathroom. He hoped the shower would get rid of his current thoughts.

At night, Gaster was staring at the ceiling, deep in thought. Even though he cooled off since his reading session, the thoughts of intimacy with Patty didn't leave him. Because he couldn't deny that he liked the idea of him engaging in the act of love with his girlfriend. Gaster then turned his head at his right, to see Patty sleeping deeply and peacefully. He smiled faintly, yet tenderly. "Isn't it a little wrong, though?" - the skeleton asked himself - "She's yet so innocent… We're not even dating for very long." It has been a few weeks, probably a month and a half, since Gaster and Patty entered in a relationship. Thus, Gaster thought it might be a little too soon to start thinking about making love. Patty herself might not even be ready for this just yet. "We're a couple for such a short time…" - Gaster mused - "...Yet, it took her this long to change me." Patty indeed changed him in a way. During his entire existance, Gaster believed he was incapable of falling in love. Romance and intimacy has never really been part of his thoughts. But when due to unfortunate circumstances, he ended up in the psychiatry ward, a mental patient nextdoor ignited that new spark in him before he knew it. Just like that, the cat monster awoke those new strange feelings. Something about her just made him want to be with her, to protect her from harm just like he did with his children, but also have physical contact, like holding hands or kissing. "Just what have you done to me, Patty..?" - Gaster mentally asked, as he stroked the blonde hair, making the cat woman's ear twitch. As he looked at the sleeping figure of his girlfriend, Gaster realized that Patty truly was irreplaceable. She made him want to try being for her the man she deserved. And because of this, Patty was the only person in the world he'd ever want to bare his body and SOUL for. Gaster really wanted to take their relationship on the next level. But did Patty want this too? The only way to know was to ask. Those were Gaster's last thoughts before he finally drifted off to sleep.

The next day Gaster and Patty were sitting in the garden, talking and enjoying the cool air of a late summer evening. They had the house just for themselves, since Gaster requested Noelle to take the children for a sleepover at her place. The young woman was a bit taken aback, but complied to the request nonetheless. She must've wondered why Gaster suddenly wanted Sam and Piper to sleep at her place, considering the restricted number of bedrooms in her house. Though, Gaster swore that he then briefly saw realization in Noelle's eyes, as though she guessed his reasons. In any case, she made no commentary and took the kids in for the night. Thus, Gaster and Patty would be alone for the whole night and the following morning. For the moment, the couple was sitting outside, gazing at the dusk and stars, while the cat monster was telling a story of how she once got lost in Waterfall as a kid.
"I don't know how it happened. All I know is that one moment I'm near my parents, and that the next one they're nowhere in sight." - Patty was saying - "I must've got so distracted in my playing that I didn't notice getting too far away from my parents."
"Why am I not surprised?" - Gaster asked, his voice holding no malice, just amusement.
"Aw, sush you." - Patty replied playfully - "Mind you, I was a good child! Well, except the times I got lost… Those times, I gave my parents some trouble… Luckily, they still were very patient with me."
Gaster noticed that Patty's golden eyes dimmed for a brief moment, surely due to thinking of her late parents. But the shine returned the next moment, and she pursued her telling.
"But guess what I was playing? I was pretending to be a traveller, who followed stars to find their way. The ceiling with incrusted gems was just so perfect to play such a game! Ironically, following stars is what made me lose my way in reality!" - Patty said with a small giggle - "I was a silly kid, I know…"
"And you grew up into an equally silly adult." - Gaster replied, rolling his eyes.
"Which I'm proud of." - the cat woman slightly raised her head with pride.
"As you should be." - Gaster said in a whisper, stroking his girlfriend's cheek.
The two then leaned to each other so the lips could meet the teeth. The couple shared a lingering kiss, slow and loving, yet with an increasing passion. Gaster held Patty close to him, burrying his hand in her blonde hair. But then Patty pulled away, though keeping their foreheads linked together. Shivering, she said:
"Could we maybe… go back inside? It's getting a little cold."
"Of course we can, Patty."
The skeleton then took her hand, after what the couple stood up and walked back inside their house. The evenings were getting cooler, since autumn was coming. Yet Patty was wearing just a vest above her summer dress, and thus it was no wonder she was chilling. Gaster would've lectured her for not wearing slightly warmer clothes, those that would be better suited for the recent change of weather. But he let it pass, exceptionally, because he had other things in mind. He and Patty sat down on the couch, and it didn't take him longer than an instant to claim her lips again. Patty instantly melted from it, since she adored kissing sessions with her beloved skeleton. After a not too long moment, Gaster's mouth then moved from her lips to her neck. Patty let out a small gasp, tightening her grip on Gaster. This was something new. Gaster had never kissed her neck before. His kisses have always been for her lips, or sometimes for her hands. Now, as he was kissing and gently nibbling her neck, Patty blushed but took pleasure in it nonetheless. She really liked this. But then, Gaster surprised her by opening her vest and planting more kisses on the furred flesh that wasn't covered by her dress. This made Patty almost lose her grip on him, her limbs momentary turning like cotton.
"Gaster…?" - she asked him breathily, as she felt her cheeks flush more.
The skeleton stopped his assaults to look at his girlfriend. The look in her eyes was mostly questioning. Her cheeks took a darker tone, but Gaster was unable to tell if she liked what he just did to her or not. Taking her hand in his, Gaster said:
"Patty, I... I realized that you are very special to me... in a way I'd never expect. I know that we've been dating for a pretty short while, but... but I feel I truly want to bring our relationship to the next level. I... love you, Patty. And you're the only one I want... this with."
Patty was looking straight into his eyesockets, feeling moved from his words. Gaster then squeezed her hand gently, before adding:
"But if you think this is too soon, or feel you're not ready... I'll understand. The choice is yours."
"...I..." - Patty paused, bringing her thoughts together, before saying - "...I've actually been dreaming of this lately... of you and I being... like this. Like a man and a woman who truly love each other... It feels right to me."
"So, what you're saying is...?"
"I want this as well, Gaster." - Patty clarified with a smile - "It's true we haven't been together for very long, yet it feels that things are just like they should be."
Saying no more, the couple kissed again. Gaster slid off the vest from Patty's body and then, breaking the kiss, he stood up from the couch never letting go of Patty's hand, as in a silent invitation to follow him. The cat woman couldn't help but smile in response and, after she kicked her sandals off her feet, the couple went upstairs. When they made it to their bedroom, Gaster closed the door behind him, before trapping Patty in his embrace again and savouring the taste of her kiss. They walked to their bed, while never breaking the kiss. Until Patty felt the soft mattress against the back of her knees and the two almost collapsed on the bed. But that didn't happen, since Gaster had a strong hold on his girlfriend, who just ended up sitting on the mattress. Gaster then broke the kiss and noticed that Patty was shivering, slightly. He wasn't an expert on the matter, but it didn't look like to him as though it was in excitement.
"Patty, are you afraid?" - he asked in concern.
"...A little." - his girlfriend admited.
"Do you... want to stop?"
"No. I really want this." - Patty shook her head, then looked down - "It's just that... I'm kinda nervous since I've never done this before, and... they say that the first time doesn't always go as well as you expect."
"I've never done this either, but..." - Gaster slid his hand under Patty's chin to make her look up at him - "I'll do my best to make it a pleasant experience for you. Just tell me if I do something wrong, alright?"
"Alright..." - Patty breathed out, as a smile made its way back to her face.
Gaster kissed Patty's lips briefly, before instructing in a whisper:
"Now... lie down and try to relax."
His girlfriend slowly switched to a lying position, breathing out longly, while her tail still fidgetted some in nervousness. His eyes always fixated on Patty, Gaster started to slowly unbutton his white coat. Patty's gaze was following the movements of his skeletal hands, as they went from one button to the next, purposely pausing in between. The cat girl couldn't help but blush at how Gaster managed to turn this trivial and daily gesture into something sensual. After Gaster undid the last button, Patty looked up at his face. She couldn't tell what he was thinking, Gaster's face being unreadable. The skeleton then slid off his white coat - the garment representing his past pain and sins - and threw it at his right in a quick move - getting rid of this symbol, ready to open his body, heart and soul for his lady. The thought of the symbolism made Patty's heart skip a beat. After Gaster swiftly slid his shoes off his feet, he crawled on the bed to position himself above Patty. The two looked into each other's eyes in silence just for a moment, before they locked their mouths in a kiss once more. It was filled with deep passion, and Patty barely registered how Gaster slid off the elastic from her hair, to make it fall loose. Soon, Gaster's hands slid down and started to experimentally caress Patty's body through the fabric. Gaster figured she'd probably be more comfortable if she was first touched through her dress. When his hands roamed over unusual areas, Patty's breathing quickened and she clenched at her lover's shoulders.
"Not good..?" - Gaster asked, concerned.
"K-Keep going..." - Patty replied with a light nod - "All's okay."
Gaster then started to kiss all over her neck and shoulders, which visibly made Patty loosen up. Her heartbeat was way too fast now, she really loved this. Her furred skin being granted kisses from Gaster felt truly amazing. As for Gaster, he figured he loved to kiss his beloved all over her flesh. After sending a quick glance at her face, and seeing she was at ease, Gaster carefully slid his hands under her back and found the zipper of her dress. When Patty heard the sound of her zipper, she shut her eyes close, out of embarrassement and mild fear. She didn't move when she felt her beloved to slide the dress down and off her body. After a moment, she dared to open her eyes. She saw Gaster marvel at her, his eyesockets glowing pink (out of embarrassement). Instinctively, she tried to cover herself, but Gaster grabbed one of her hands in his own and gently kissed it.
"You're beautiful." - he then said.
Patty managed a light smile at his compliment. Gaster then kissed her on the lips, this time sweetly. This made some of Patty's tension leave, and soon Gaster resumed to caress her body, as well as occasionally grant it kisses. If Patty's heart didn't go mad sooner, it certainly did now. She felt just so happy and so loved! And for the first time in her entire life... she felt truly be a woman. Patty didn't know her age, she stopped caring for many years now. She was what some would call her "young at heart". All she cared about was that she was a girl, her age being irrelevant to her. She was a young girl, and the knowledge was enough for her to be happy. But now, as her body was being given pure pleasure, she was a woman. His woman.
"Gaster..." - she softly moaned the skeleton's name.
Hearing her say his same with such tenderness, love and desire made Gaster's SOUL swell. It sounded like music to him. Gaster looked at his girlfriend, her cheeks tainted by a light blush, her pupils dilated due to the darkness of the room and her own excitement, her blond hair spread all over the pillow... The sight made him wonder if he was dreaming; he could barely believe that this was really happening. He was discovering the mystery that was the body of a woman. But not of any woman, one of the woman he loved. It felt a bit surreal, never had he thought he'd ever come to this in his life. Especially not after all the wrong he's done... But here they both were, and despite everything she knew about him, Patty loved and wanted him. Gaster then felt Patty tug at his white turtleneck, obviously attempting to undress him. He tensed a little at this, but then he summoned his blue magic hands to gently grab her wrists and pin them at both sides of her head. Patty let out a small huff of disappointement, and Gaster responded with an almost invisible smirk. But Patty noticed it, so she gave him a playful glare. Gaster then removed the turtleneck, exposing his upper skeletal body. Patty was looking at his body with admiration, and her heart fluttered at the sight. She then tried to reach her hand to his ribcage, wanting to touch it, but Gaster's magic hands didn't let her. She tried to lift her hand again, but the magic one had a strong, yet gentle, hold.
"Gaster, please..." - she begged him.
The skeleton leaned back to her and asked with a hushed and sly tone:
"Please what?"
Patty's cheeks reddened more at this, but managed to answer, albeit shyly:
"Please... Can you… let me touch you..?"
"Can't refuse you when you ask so nicely." - Gaster replied with a smile, and his magic hands vanished.
The couple then took a sitting position and Patty laid her hands on Gaster's ribcage. Her caresses started shy, but soon enough gained in confidence. She'd let her hand slide down across the ribcage, or trace each rib with a finger. Her ministrations seemingly provided some pleasure, since Gaster's body started to tremble, his bones rattling mildly.
"Your body's beautiful too..." - Patty said, before kissing one of the ribs - "You have so perfect ribs."
It was now Gaster's turn to blush. Patty then kissed his sternum, while one of her hands stroked long his spine. Gaster let out loud sighs, the feeling of Patty's touch and kisses being undescriptible. It was as though the bones she touched were being given a treat of healing magic... no, it was even better than that! The SOUL inside his ribcage was glowing in a very bright light at this point, this was how good it all felt. Patty noticed the increasing brightness of her lover's SOUL, and her curiosity and fascination for it grew. She wanted so much to reach under the ribcage and just touch it... but she guessed she should perhaps ask Gaster's permission first. Patty looked up at Gaster's face and with a hesitant tone, she started:
"Gaster, is it okay to... I mean, would it be alright if I..."
But she looked nervous and couldn't finish her phrase.
"What is it, Patty? At this point, you can ask me anything." - Gaster said genuinely.
"May I... touch your SOUL?" - Patty finally dared to ask - "...Please?"
A moment of silence passed. Briefly, Gaster's eyesockets glowed purple. The idea scared him. Feeling a bit guilty for suggesting such a thing, Patty hurried to say:
"But it's fine if you don't want me do this..!"
"You can." - Gaster said quietly.
Patty looked him in the eyes, as though silently asking him if he was sure about that. Gaster then summoned his SOUL outside of his ribcage, to make it easier for physical contact. Patty looked at the SOUL with a look of wonder on her face. She had at her reach the culmination of Gaster's whole being, the heart that kept him together. The white glowing heart was rather big and beautiful. There were some cracks on it, and Patty guessed where those came from. Slowly, Patty reached her hand to the SOUL and after a moment, carefully laid her palm on it. She heard Gaster breathe in shakily, so she looked up at him and quickly retrieved her hand.
"Did that hurt?"
"No..." - Gaster shook his head and a light smile curved on his face - "It actually... felt very nice."
With a smile of relief, Patty brought her hand back to his SOUL and slowly traced its shape with her finger. Gaster's breathing rate fastened, just a little. Patty then looked at him again, and said:
"Your SOUL is so beautiful... I really like it."
Those words alone overwhelmed Gaster with many emotions at once. On one hand, he thought he didn't deserve this compliment, that his SOUL was beautiful only outwardly. But on another hand, he felt a rush of happiness cross his whole being. Patty saw him as someone worthy of her love. Without saying a word, Gaster put his SOUL back inside his ribcage and pulled Patty in a deep kiss. Their kiss lasted for a while, and while never breaking contact, their hands caressed each other with infinite passion. Soon, with Patty's help, Gaster got rid of his brown pants and the couple returned to the lying position. Gaster's hand was burried in Patty's hair and their legs got entangled. When Gaster pulled away to allow Patty to catch her breath, the latter was met with a marvelous sight. Gaster's eyes were glowing green very brightly. He was truly happy. With a smile on his face, Gaster breathed out:
"I love you, Patty... I love you so much."
"I love you too." - Patty replied, caressing his cheek - "Like I've never loved anyone before."
At that moment, something amazing happened. Gaster's SOUL glowed brighter than ever before, and Patty's SOUL made itself visible too! The couple looked into each other's eyes with mild surprise, but also with deep emotion. If their SOULs were ready to bound that way, didn't this basically confirm that they had "true love"..? Gaster and Patty then shared anther tender kiss, and the proximity of their bodies made a current pass between the two SOULs. The two gasped from the strange feeling. It was strange, but definitely not unpleasant. It didn't take long for them to get used to it. And then, it started. They could feel that magic flux passing in between their SOULs, the connection of the two essences of magic and life... That connection soon got an impact on their bodies too. It felt like it was on fire, but also like it was being carressed all at once... The feeling was simply undescriptible. Patty scratched Gaster's scapulas out of the overwhelming pleasure. It was so intense, she thought she'd lose all the remainings of sanity she had left. In between moans of pleasure, she breathed out Gaster's name many times. Gaster too was whispering the name of his lover in her ear, but also repeating how beautiful she was and how much he loved her. It usually wasn't a very easy thing to say out loud, but in this moment, when their SOULs were almost one, he let his feelings and words go free. They kept magically making love for a while, they felt as though they were both in their own personal heaven. At some point, Gaster took Patty's hand in his own and the fingers interweaved together. The hands linked in a very strong hold, which sank into the mattress. Feeling the pleasure reaching the ultimate peak, Gaster and Patty moaned each other's names. The light in between their chests emitted a short bright flash before dissipating. Gaster's SOUL regained its normal glow, and Patty's one was no longer in sight. The couple laid in their position yet for another long moment, to recover their spirits. Slowly, letting go of his grip on Patty's hand, Gaster rolled on his back, before bringing his girlfriend closer to him. Patty laid her head on his ribcage, closing her eyes in contentement. Gaster then carefully slid the blanket from beneath them to cover them both. It didn't take long before he felt dampness on his ribs and as he looked at Patty, Gaster saw that she had tears in her eyes. Worried, he asked:
"Are you crying..? Do you... regret this..?"
"No..." - Patty looked at Gaster and smiled through her tears - "Never would I regret tonight. I'm just very happy... Since my school years, I'd often overhear other girls talk about their first times. I... never dared to hope that I'd come to experience this myself. That I'd have my first time with a man I love..."
Gaster wondered for a moment how it was like for Patty, to live knowing that other people saw her, before anything, as a crazy person. That she couldn't truly hope for someone love her that way.
"Did I make it… nice for you?" - he asked in concern.
"You made it special, Gaster. And I'll remember tonight forever." - Patty replied, pecking him on the cheek.
"So will I." - Gaster replied, kissing her on the temple.
With a smile, Patty rested her head on his bare ribcage again. Gaster was gently rubbing Patty's shoulder, which made her doze off fairly soon. The skeleton then closed his own eyes too, feeling that for the first time in a very long while, both his mind and soul were fully at peace. It didn't take long for him to join his girlfriend in the land of dreams.

A/N: I must say, I never thought I'd write a M-rated story someday, but then I did it. But it's the only time I would've ever done this, so don't ask to write more of that stuff. It was a one-time thing.

I wanted to explore this aspect of Gastty relationship for a while, but it took me some time to overcome my fear and embarassement. But thanks to a friend's advice, I got the courage to make the jump. Please, don't judge me! DX And don't judge the content too harshly…
Anyway, it was a nice trip out of my zone of comfort. And I don't regret anything. ;)

Just to clarify: touching the SOUL isn't a sexual thing. Gaster says it feels good, but it's because he lets it be touched by the person he loves and trusts the most. And she's being very gentle. (Carelessness may even hurt, I think.) It's still an intimate gesture.