It's another sequel story to my "Once Upon A Handplate" fanfiction. If you haven't read it, you'll be kinda confused about some things and characters. It's another story of Gaster and his girlfriend Patty (they started to date at the finale of OUAH). Patty is my OC. Also, to avoid confusion, Asriel is (obviously) alive again and he's a young adult.

Disclaimer: I don't own "Undertale" or its characters, they belong to Toby Fox. I don't own "Handplates" and its version of Gaster either, both belong to Zarla. I just own Patty. :)

Gaster was sitting on the couch in the living room, reading a book. He was alone in the house, since Sam and Piper have been invited by Pupamy to sleep over at his place for the night. Gaster was glad that his children had a best friend who they could have good fun with, and thus he allowed them to have their sleepover. Patty wasn't at home either, since she went out to shop. But she was gone for a while and it was starting to get darker. As the street lamps got turned on, Gaster thought that Patty should return in no time. Though, he couldn't help but wonder what was taking her so long and hoped that nothing bad happened out there. The skeleton couldn't just go out and look for her, since he was allowed to go outside at certain hours of the day only (as a condition of his supervision). But before Gaster could actually get worried, he heard two familiar voices from the outside. Gaster stood up from the couch and discreetely looked through the window near the door. Patty was standing at the treshold, seeking for her keys in her handbag, but she wasn't alone. She was with Asriel, who was carrying two of her bags. The young prince was smiling widely and had the expression of someone who was pleased to help. Or at least, that's what Gaster guessed it to be. The two seemed to be engaged in a very pleasant conversation. When Patty found the key and inserted it in the keyhole, Gaster stepped back. When the door opened and the two monsters entered the house, Gaster said:
"Good evening, Prince Asriel. It's a surprise to see you here at this hour."
"H-Howdy, Uncle Gaster. I met your lady near the shops and decided to help her carry her bags!" - Asriel replied with a bashful blush.
"Yes, Prince Asriel and I had a very nice chat on our way here. He makes a lovely company!" - Patty said sweetly, her mouth curving into a lying cypher 3.
"Hehe, don't exaggerate… I have less things to say than you do." - Asriel replied modestly - "Truly Gaster, she was making most of the conversation!"
"So, may I assume she was in a babbling mood?" - Gaster asked, while directing his gaze at Patty.
"It's not a bad thing, is it..?" - Patty looked up at Gaster with a slightly embarrassed expression.
"Hey, there's nothing to be embarrassed about!" - Asriel said with a genuine smile, before friendly wrapping an arm around the cat monster - "You are an adorable babbler!"
"Aw, you're making me blush..!" - Patty replied as her cheeks indeed grew pink.
At the two monsters' exchange, Gaster's mind was slowly taking a darker turn. It did catch the nice compliments the two were telling each other. "'Lovely'? 'Adorable'?" - the skeleton mentally repeated the words. It wasn't abnormal for Patty to use endearing words to describe people, nor was it for Asriel to be a very nice talker. Yet for some reason, that little friendly exchange didn't put him at ease. The shadow of some alien unpleasant feeling got concretized when Patty then suddenly offered:
"Would you like to stay for a cup of tea or coffee? To thank you for carrying my bags and keeping me company."
"Sure, that sounds like a lovely idea!" - Asriel replied with a joyful expression - "You don't mind Uncle Gaster, do you?"
"Of course I don't. My home's your home…" - Gaster replied, but did so half-heartedly.
Asriel nor Patty noticed the lack of enthousiasm in his tone and moved to the kitchen. Gaster sat down on the couch and resumed the reading of his book. But he was pretending than anything else. He lost all will to read by now and, while his face facing the pages, he focused on what was going on in the kitchen at his left. He could hear the noise of the water boiling as well as the small glass commotions of the mugs. The two monsters kept talking very nicely, and it sounded almost like Asriel was charmed by Patty and her sweet nature. It didn't take long before Asriel requested Patty something that caught Gaster's attention.
"If it's not asking too much… Would you mind to show me some of your drawings and paintings? I'm really curious to see those!"
"I don't mind showing my artworks at all!" - Patty replied with her usual joy and smile.
"So Asriel already knows about her passion? Has she been telling him about it during their walk..?" - Gaster thought to himself - "And it already caught the young prince's interest…" Gaster saw Patty walk out of the kitchen and in the direction of the small study. It took her only a few moments to show up again, holding a folder in her hands. When her gaze met Gaster's, she gave him her usual nice smile that Gaster was unable to return this time. Once back in the kitchen, Patty served Asriel a cup of tea and then the two proceeded to browse through Patty's artworks. There were many of them and so it was taking some time. Gaster listened how Asriel was saying comments of amazement, while Patty was providing additional details about some pictures. Listening to their conversation intensified the strange unpleasant feeling that Gaster didn't dare to name. It felt almost like he'd get sick, but it wasn't quite that. He turned his head to the kitchen and after a moment of consideration, he decided to go join the two fluffy monsters there. And he had joined them at a very interesting part actually. Asriel and Patty had almost finished browing through the artworks and Asriel spoke up his mind:
"Really, you are a very talented monster, Patty. You should show your artworks to more people!"
"Aw, thank you. Well, I'm already showing them to Gaster and his children. They say those paintings are good. The King and Queen also saw some of those and-"
"No, I mean… you should use your skills in the professional area." - Asriel clarified his earlier statement - "When I look at your drawings, I remember my childhood, notably some colorful books I used to have. Pictures always helped me to immerse into a story. So I thought… Maybe you could be a book illustrator?"
Both Gaster and Patty were surprised by the prince's idea.
"I... I've never thought about this before..!" - the cat monster said after a moment.
"You definitely should consider this. I think that with your talent, any publisher would accept your offer!" - Asriel flattered Patty's skills again, his eyes shining with genuine enthousiasm and faith - "Just try and you'll see!"
"You really think my works are this good..?" - Patty asked with a light blush - "Oh my, nobody's ever said so much about it and with such seriousness…"
"Really now? That's a shame." - Asriel commented, then looked at Gaster and added - "You really should praise your girlfriend's art more often, Uncle Gaster!"
"I do praise it, I'm just not an expert." - Gaster replied, then averted his gaze.
Even though Asriel meant no ill with his words and said those with humor, it did hurt Gaster's SOUL. It hurt, and not just a little. After a moment of processing, Gaster came to the conclusion that he really didn't like the way Asriel was acting around Patty. He was being way too friendly towards her, encouraging her more than a person who didn't know her that well should. And as he was looking at the goat prince, Gaster realized that for the very first time in his life, he wasn't seeing Asriel as the prince of monsterkind or as his younger foster brother. Gaster was seeing him as a man. A man that he at the moment wanted out of his sight, even. Inhaling deeply, Gaster spoke up:
"Asriel, you must be getting tired. It is pretty late now."
"No, I'm actually fine. Can stay awake yet for a while!" - Asriel replied, not catching the drift.
"But your parents must be worried about you. You shouldn't make them wait for you, or you'll make them anxious." - Gaster said, hoping the argument would convince Asriel to go back at his home.
"Oh, but that's why we have cellphones now!" - Asriel said with an amused smile - "If they do get worried, they'll text me. Besides, I'm an adult and a future king. I can go out for as long as I like without being kept on a leash."
Gaster sighed almost too loudly. Was Asriel really not getting it, or was he doing this on purpose? Just for how long Asriel was planning to hang out in his house? No, Gaster couldn't allow Asriel to flatter Patty for much longer!
"Asriel. I think that you really shouldn't make your family wait any longer." - Gaster said with an insisting note - "You will upset them if you return home too late. Trust me, you will."
Asriel was surprised by Gaster's bizarre behavior but when he saw the look in the skeleton's eyes… he understood that arguing back or questioning it wasn't an option. He didn't understand what was going on, but he knew that he was probably becoming a nuisance to the host. He awkwardly stood up from his chair and said:
"Well... I suppose you're right, Uncle Gaster... I really should go. Thank you for the tea, Patty… and for showing me your paintings. It was a real pleasure watching them."
"You're welcome to pass by anytime!" - Patty replied with her usual sweet smile.
"Thanks… Have a good evening Patty, Uncle Gaster…" - Asriel said.
"Yes, yes. You too, Asriel." - Gaster said, sounding quite dismissing.
As he turned the doorknob, Asriel couldn't help but wonder: "What did I do wrong, though..?" After the prince of monsters went out of the house, Patty's expression grew pensive for a few moments. Then, she looked up at Gaster and asked with a slow unsure tone:
"Is my mind playing a trick on me or... you really wanted Asriel to go away…?"
"No, your mind isn't tricking you. Not on this point, at least." - Gaster said a bit coldly.
"W... What is that even supposed to mean..?" - Patty asked with a confused face.
His eyesockets flashing with a red glow, Gaster said harshly:
"I mean that maybe you don't even really know who you are in love with?"
Gaster immediately regretted saying this out loud. It took a moment for Patty to process the meaning of those words, and as her eyes displayed a hint of realization, Gaster quickly turned around and walked in the direction of the study. Patty, who wasn't yet sure how she should feel about what he said, called out after him:
"Gaster, wait..!"
But the skeleton ignored her and closed the door behind him. He felt ashamed for telling Patty what he just did; he hadn't had the courage to watch the look on her face when the meaning of his words hit her. Gaster sat down on the chair and put his head in his hands, resting his elbows on the desk. His eyes started to glow red and purple at the same time. "I shouldn't have said that…" - he thought - "I certainly offended her and insulted her mind…" And yet, he really needed to let out those unpleasant feelings somehow. He knew he did it in the worng way, but what else was he supposed to do? Asriel was being so nice to Patty and encouraging of her passion, even suggesting to apply it in the professional area. The way he had praised her skills was to charm a woman's heart. He had actually flattered her and made her blush. The memory of the drawing representing Asriel and Patty found in the psychiatrist's office months ago replayed in Gaster's mind, making his SOUL feel as if being squeezed. Gaster didn't like to feel that way, it was making him miserable. But he couldn't help it, he just hated the idea of Patty being with another man, including his prince. He hated that Asriel was a better option for her than he was. The poisonous thought made Gaster let out a small whimper, while his vision got blurred with upcoming tears. He didn't react when he suddenly heard a knock on the door.
"Gaster, can we please talk?" - Patty asked from the other side - "May I come in?"
Since Gaster didn't reply anything, Patty seemingly took this as an invitation to come in. When she saw Gaster sitting there, his head between his hands and not even looking at her, Patty walked to him slowly.
"Gaster, even though what you said… and the way you did… wasn't very nice, I'm not mad at you." - she said.
The skeleton didn't react to her words. Patty gently laid her hand over Gaster's shoulder, and the man tensed at her gesture. Patty went on with a gentle tone:
"I just want to talk about this... to understand what's going on in your mind."
Another silence followed. Patty knelt down so she was more at his level and she requested again:
"Can we please... talk about it? Please… tell me what's wrong."
After a moment, Gaster finally lowered one of his hands and turned his head in Patty's direction. At first he didn't say anything, but after looking deep into Patty's expecting yet patient eyes, he finally spoke with a trembling voice (just like were the signing magic hands):
"I... I got jealous, Patty…"
He paused for a moment, then he averted his gaze and a signle tear fell down on the flat surface of the desk.
"And I'm sorry... I didn't mean to snap at you… But it just hurt me so much… I couldn't bear it… I'm sorry for snapping at you, Patty…"
"Hey, hey, it's okay." - Patty said, gently rubbing his shoulders - "I'm not angry at you. I was kinda upset, but it's alright now."
"No, it's not..."
"Then it will be." - Patty smiled at him - "But what exactly made you feel jealous?"
"It's many things at once… Asriel was the first person to suggest you becoming an illustrator, while I never thought about this."
"But that's no big deal. I never thought of this either."
"It's not just that... Asriel is the kind of man you deserve, who'd make you very happy. He's nice, polite, rich, funny… and charming. On top of all that, he's an actual prince. He's like a fairytale prince girls dream of, like all those men from your romance novels. While I... I'm nothing like them."
At that moment, Patty wrapped her arms around Gaster in a warm hug, making him freeze.
"Why would I want a prince when I can have a cute nerdy scientist?" - Patty said with a smile.
Gaster's cheeks became as red as tomatos. The cat monster giggled at his reaction. Gaster looked up at his girlfriend with a curious look. Patty went on:
"I only need you, Gaster. Yes, I used to dream about princes, heroes from books and movies. But after I met you, and after you had to leave the hospital… I realized that no man could make me happier than you would... And you did."
"But how..? I... I'm a sinner Patty. I've tortured, lied, abused... killed... and messed up with space-time fabric out of a selfish whim. I'm not very good at properly showing affection or expressing my feelings. I have no clue of how to be 'romantic', and I can't even take you on a night date because of the electronic supervision..! I have nothing to offer you Patty..."
"Nothing? But you already offered me something very precious!" - Patty disagreed, shaking her head.
"I did..?" - Gaster arched an eyebrow.
"Yes. You offered me your SOUL." - Patty said, looking into his eyes lovingly - "And your love. And you did for me much more than you give yourself credit for."
"Like what? I'm really curious to know."
"You welcomed me in your house, you're making sure I take my pills, you watch me paint with interest, you make me red jello once a week… You even made a several layered rainbow jello once! That was a very nice surprise." - Patty's eyes shone at the memory, making Gaster chuckle - "Also, we have interesting conversations, we discuss books, we have long checkers plays… You keep winning, but it only makes me more eager to play against you. And finally… you understand me better than anyone ever tried to. You did a lot by just being on my side."
"Coming from your mouth, it sounds as though those things are a lot." - Gaster commented with a sad smile.
"Because it's the smallest things that are the most valuable." - Patty replied honestly.
Gaster looked into Patty's eyes and saw in there nothing but love, warmth and understanding. He then finally wrapped his arms around her, bringing her closer to him (by this making her sit on his lap) and burried his face in her blond hair.
"You truly are something, Patty. I really am sorry for my earlier harshness... I'm just... I'm just so afraid that I'll eventually lose you..."
"Gaster... Look at me." - Patty requested him and after a moment, he did as she asked - "You will never lose me. I won't ever leave you, I'll be there for you as long as you want me around. That's a promise."
Gaster tightened his grip around Patty, feeling moved, and after a moment of comforting silence, he decided it was a good moment to speak up his feelings freely.
"I love you, Patty." - he said quietly
"I love you too." - the cat monster replied as quietly, with a loving smile.
Their faces then leaned closer to each other, before sealing their feelings in a tender kiss. Gaster felt secure again. Patty just promised him she would never leave him, and he believed her. At that moment, Gaster knew that he was loved. And Patty, she hoped she could communicate to him just how much he meant to her. The couple remained in that loving and comforting embrace for a long while; actually not letting go of each other for the rest of the night.

A/N: As you can see, if Gaster got jealous it's not because he's possessive, but because he's insecure. He's afraid that Patty will realize that another man can give her "more" and that she'll leave him. He thinks that he's not good enough for his girlfriend. Don't worry, Gaster's not overwhelmed with those angsty thoughts all the time, but seeing Patty with Asriel just triggered some insecurities inside and it just took over him. And the knowledge that Patty was once "in love" with Asriel during one of her schezophrenic phases didn't help. Asriel is a dreamy guy in monster standarts, after all.

Patty actually doesn't remember that phase, actually. Since it was long ago and at a time when she wasn't taking her pills, it's now all blurred in her memory. She does vaguely recall that she liked Asriel for his image at some point, but she doesn't remember having fantasized about him and her actually being engaged. Nor does Patty recall having once drawn herself with the prince dancing in the ballroom. It's partially due to the fact that the drawing had been taken and kept by the psychiatrist.

Gaster had lost many people in the past. Most of them were during the war, but there's also the instance when Toriel left and the royal children died. It's true that they eventually returned and that everything's well now, but the feeling of loss back then was very strong and has left an imprint. It was very painful and Gaster doesn't want to experience this again.

But hey, cheer up now. Patty won't ever leave him! :) She loves her adorably salty scientist too much! ^^