Marshall knew exactly what he wanted to do. It was really more of who he wanted to do, but that was besides the point. He had to approach it delicately because whenever he brought it up she'd get totally flustered and defensive, but when she did it was bedroom now. Although they've only done it twice, but that is also besides the point. She had explained to him that it wouldn't be an everyday thing which soured his mood. Yeah he respected her and frankly wouldn't argue to spare his cheek meat, but a girl with a body like that was hard to resist. It wasn't only her body he was attracted to. The thing he really liked was her strong attitude and rockin' personality. It really showed when they do those kinda things, and just the thought of being in her command again made his jeans feel so much tighter. The plan of approach: subtle, yet straight to the point. She usually reacts better to that kinda stuff. He was depending on Cake not being there considering he called up Gumball and virtually begged him to get Mochro to hit up Cake and get her away from the tree house. Kitty was a minor distraction usually, but if he wanted to simply peck Fi on the cheek or hold her hand she'd go fucking nuts. Difficult to deal with, yet it still didn't stop him.

As he approached her house he quickly hid behind one of the branches. Cake was just leaving, which made him grin. Perfect. Now bunny-babe was all to himself. He waited for her to disappear over the grass hills to the candy kingdom before floating down to the front door and knocking politely. It was a bit out of his character, but he wanted to butter her up as much as possible. When Fionna opened the door she saw her boyfriend standing with his usually cocky smirk and his umbrealla that prevented him from getting burned to a crisp. She gave him a skeptical look. Fionna may be a bit spacey sometimes but she's not completely oblivious. Cake had just left, and she wondered if he had anything to do with it...

"Uh, hey" she greeted.

"Hey, babe. You wanna hang?" He inquired.

"Um..." she looked back to the ladder which lead to the game she was currently playing on BMO then back to his incredibly charming smile.

"Sure, just let me finish my game" she said pointing her thumb upstairs.

"Nice" he invited himself in and walked past Fi, giving her butt a light slap as he passed by her to hopefully give her a hint of why he was here.

She squeaked and got completely red in the face. Just because they did it twice doesn't mean he can just touch her body like that without permission. Talk about violation. She grumbled a little and closed the door as he tossed his closed umbrella in to the umbrella bin and made his way up to the main room. BMO was set on the table along with a soda and a book about swords. He smirked, classic bunny.

"So what've you been doin' all day?" He asked looking around.

"Well, Cake just left so I've been trying to play on BMO, but it appears I have a guest" she snarked and walked past him to the turquoise machine. He chuckled.

"Feisty bunny. I would've come another time if I'd known you'd be moody" he said and floated over her to watch the screen.

"I have a feeling the reason Cake is gone is because of you" she accused.

"Pffff! No way, what are you talking about" he replied in a joking manner, obviously lying. She glared up at him for a second and returned to her game.

"So why did you need me alone?" She questioned.

"Actually you're not alone, you're playing on BMO but..." he reached down and undid the batteries on the back and let the machine die temporarily. "...that's easily fixed" he spoke in her ear and drifted his hand over her shoulder. Her body instantly tensed up and she glared at the blank screen.

"I was playing that" she informed him. Damn, it was hard to get this through to her. She wasn't usually this upset when...oh wait. He sniffed the air. Yup, there was definitely blood nearby but no where in sight. He looked at his bunny with a bit of pity.

"Fi, don't get upset or embarrassed, but are you on your period?" He asked. Her glare shot up to him and she blushed furiously.

"N-no! Just because I'm being moody doesn't mean I'm on my period!" She nearly shouted and crossed her arms.

"Babe, vampire" he reminded her by pointing to his nose. Her glare was replaced with mortification, and she felt like she was going to cry. Damn these stupid hormones! Fi's a tough bitch and she is not crying in front of her boyfriend.

"I...I'm sorry" she murmured looking away. Confusion flickered across his face. Why was she sorry?

"Babe, there's nothing wrong with having your period. It's normal and healthy, and not something to apologize for" he sat down next to her and put his arm around her shoulders in a more chaste and affectionate way. She leaned her head against his shoulder and he took a hold of her hand.

"But I'm being a real bitch right now" she pointed out quietly. He sighed.

"Babe, I'd be like 10 times more bitchier if I was going through what you are. And you gotta put up with this shit once a month. It's fine" he assured her.

"I'm not doubting that" she mumbled making him laugh.

"But you got us alone and now we can't-ah!" She groaned and clutched her midsection, her head slipping so she was laying across his lap and cringing at the pain. Marshall felt bad for her. Fi rarely ever admitted she was in pain, much less completely buckle over from it. He rubbed her shoulder comfortingly as she grabbed his jeans from the pain.

"I'm gonna take care of you today. I promise, okay?" He told her. She nodded, not in the mood to argue with him.

"Do you have any like pain relievers? Pills that Cake gives you when you're hurt?" He asked. She nodded.

"In the cupboard" she informed him pointing to the kitchen.

"Okay, here's what I want you to do. Go to the bathroom and get a bath running. You can add bubbles and make it as warm as you want, got it?" He instructed.

She nodded and got up from his lap to wobble over to the bathroom while Marshall got the medicine. He'll admit he was weak when it came to people he cared about in pain, and he didn't really care about a lot of people. Fionna, maybe Cake, Gumball since they've known each other for so long, and his mom because it was his mom. He got out the pills and put the kettle on to the stove, heating it up as he looked through their tea bags. Sweet tea, earl grey, blue berry-ah! Chamomile. Perfect. He fixed her up some tea and searched around for some chocolate and put it all on a tray before bringing it in the the bathroom. The air was warm and misty, her clothes in a neat pile next to the tub and bubbles Floating like little islands in the water.

"Marshall!" She squeaked, covering herself with her arms in the tub and blushing as she noticed him. He rolled his eyes.

"Like I haven't seen you naked before, babe" he pointed out.

"Just because you've seen me naked before doesn't mean I want you to see me naked all the time" she argued. He rolled his eyes and handed her the two pills and her tea.

"Careful, it's hot" he warned "like you" he winked.

"Shut up" she grumbled and took the damned pills.

Fionna gladly gulped down the tea and enjoyed the warmth it spread through her stomach and already started to feel a bit better. She relaxed in her tub and leaned her head back, closing her eyes and making Marshall smile. Her golden hair was wrapped up in a bun, and her cheeks were slightly tinted from the warm water she bathed in. The bubbles covered portions of her body, but left enough for Marshall to appreciate her figure. Girls shouldn't have to suffer these kinds of things, they're way to pretty to be inflicted with pain.

"Thanks, Marsh" she said and played a bit with the bubbles with her finger.

"No problem, sweetheart" he replied and handed her the chocolate. She accepted and was suddenly happy that Marshall had barged in today.

"Why'd you come today?" She asked, although she had a good idea of why he did. He scratched the back of his neck.

"I uh...wanted to do some things, but it's fine if you don't want to with your period and all..." he said semi-awkwardly. She cocked a questioning brow.

"Some things as in...sex?" She questioned bluntly.

"Uh, yeah" he admitted. Fionna thought for a moment, she though people couldn't have sex on their periods because it was blocked off with all the blood and stuff. Also it didn't really sound good for her cramps when she remembered the slight pain of pushing in.

"I don't think you can when I'm on my period" she said. He chuckled.

"Yeah, you can" he informed her. She tilted her head in confusion.

"How does that work?" She asked.

"It works like normal sex, but with a bit of blood" he answered.

"But...would you actually want to do that? It sounds a bit...gross" she hugged her knees to her chest protectively at the thought of him disgusted with everything if they tried. He gave her an are-you-stupid look and tapped his fangs.

"Vampire, pretty used to blood" he reminded her

"and besides, if anyone ever thought you were disgusting for your normal bodily functions they deserve to get their face mauled by a bear"

She giggled.

"Just their face?" She smiled.

"And possibly their dick" he added with a grin. She laughed and smiled at him, happy he was here as he came to the edge of the tub and leaned against it.

"Actually, it'll help you in your current situation" he told her. Her eyes widen. Any chance of relief was a chance she was willing to take.

"Really?" She asked. He nodded.

"It relieves cramps" he swirled his finger in the water, pushing around the bubbles and enjoying the pink color on her cheeks. It wasn't from the warm water; it was from what he said. He could tell.

"I...I guess if...you want you..." she mumbled the rest and lowered her head slightly in embarrassment. He gave her a quizzical look, not even his vampire hearing could pick up whatever the fuck she said.

"Babe, I can't hear you when you mumble"

"I said...you can...do things if you want" she said a little louder for him to hear. He perked up a little.

"Things like..." he trailed off, hoping she would understand what he was getting at. She nodded, her face bright red like a sunburn. He smirked and pulled his finger through the water until he met her knee. Fionna watched as he traced around her knee and trailed down her shin under the water.

"Okay then, if you're absolutely sure..." he got up and floated so he was behind her. Her eyes followed him over her shoulder he rolled up his sleeves.

"...than I'd be oh so happy to do so" his smirk suddenly got dirty and she felt her toes curl in anticipation.

He sat on his knees behind her and wrapped his arms around her, barely even grazing the top of her breasts as he nuzzled against her neck. She felt his lips against her ear and clutched her knees tighter, her lungs constricting and demanding more air. This was ridiculous, he was only kissing her ear and she was already tensing up. Marshall moved down to her neck and kissed her damp skin, the soap strongly consisting of her delicious vanilla scent as he licked the water droplets. He tilted her head back slightly and kissed her clavicle. Her pulse thumped heavily under his fingers while he caressed her neck. Fionna almost couldn't believe how fast he had managed to arouse her, her heart already flutter faster than a humming bird. He could feel the blood pumping through her body and let his hand slip under the water and over her pronounced chest.

She started to lose control of her breath when she felt his nimble fingers play with her stiff nipple. It was strange how her body was so much more sensitive than before, and it made her like it even more. Her eyes were half lidded and clouded with lust when he squeezed her breast and licked the bite marks he had left the previous adventure they indulged in. There was no way to deny how much the simple swipe of his tongue excited her. Water dripped as she gripped the edge of the tub, opening her legs slightly out of instinct. Marshall noticed and smirked at the invitation. His fingers gave her breast one last squeeze before sinking lower in the water.

"Sensitive, eh?" He whispered and kissed her jaw. She nodded, how could he tell? He chuckled.

"You're adorable" he whispered. She whimpered as he touched her hip and swirled his fingers over her coarse hair.

"S-shut your mouth" She stuttered nudged her hips against his fingers.

He turned her head to look at him, his smirk making her even more embarrassed with her current state. Which excited him and prompted him to lean in and press his lips to hers. Fionna practically dissolved once he kissed her, his lips so soft and his fingers so frustrating. Like seriously it's right there, just-

"Ah!" She gasped as he cupped her sex under the blanket of water.

"Marshall" she whined and rolled her head back.

He grinned and started rubbing her slowly. His laborious fingers made her legs open wider as she now clutched both sides of the tub. She was panting like a dog and nearly breaking the tub with her death grip. The beautiful pink tips of her breasts peaked from the water each time her chest heaved. With his other hand he grabbed her chest, mercilessly groping and rolling her nipple while biting her ear lobe. She squealed and twisted her hips to quicken his lazy pace on her groin. Fionna's body shuddered as he huffed in her ear, he was turned on from the moment she gave him the okay. And this was definitely more than okay. She moaned as he rubbed faster and relished in her sounds when he slipped in his finger. Everything about her was delicious from her scent to her moans he drank it all up. Water sloshed in the tub and barely spilled over the sides, her body creating waves each time she rocked her hips. He couldn't take it anymore, his jeans way way way too tight as he snarled and pulled away, making her whimper and look to him.

"What the fuck are you doing?" She demanded to know.

He hurriedly whipped off his flannel and undid his belt in a flash. There was no time to waste, he wanted her now. She was impatient with his lack of response and found herself distracted by her stripping boyfriend. Was he...oh. Oh yes. That's exactly what she wanted. Her eyes followed him eagerly as he kicked off his jeans and walked around to drain the water slightly, his boner obvious in his jockeys. Once it was at a reasonable level he pulled down his shorts and practically leaped at Fionna, holding and caressing her body in his hands. She moaned in response, continuing to rock her hips only against his own this time. It was a good thing Marshall let the water drain or else they would've had a huge mess to clean up.

He kissed all over her chest and breasts, taking extra time to suck at each nipple and loving ever moan in between. His hasty hips rubbed against her until he pushed in and heard her groan. Her nails dug in to his back as she grinned at how much easier it was to push in. After a few times of riding the horse you get to ride even faster and longer. It took next to nothing to thrust out and back in as she felt nothing but pleasure. His face twisted with the same feeling, and he growled in to her breast before biting it roughly. Marshall lapped up the blood from her skin, the metallic sweet taste a bit watered down from the restless water but still satisfying to his tongue. She drew blood as well from his back, dragging her nails up his back from how extravagant and amazing he made her feel. Just knowing she turned him on so much that he freak if jumped her made her smile and bite her lip.

"More, Marshall" she demanded moving her hips with him. He kissed further up her chest and bit her again, finding a new kink that thoroughly excited him as he bucked against her. She squeaked and dug her nails deeper, determined to make a long lasting scar even his vampire healing couldn't prevent from becoming a long lasting scar.

"Shit" she hissed and bit back, not even trying to hold back while water somehow managed to drip slightly on the floor. He grunted and left another mark on her shoulder as pay back.

"Harder...faster" she ordered, the marks left from his teeth barely even stinging. Fionna enjoyed it when he bit her, it was probably her favorite part now. He snarled and obliged, caught up in his own pleasure that he'd follow any order she gave him. Each time he thrusted he flicked his hips, making her cry out and arch her back from the shivers clawing at her spine. Marshall was close, oh so close, but he tried his best to hold on with every inch of his being while he clutched the hot sweaty mess of desire underneath him that was Fionna.

"A-almost...glob!" She cried and felt the climbing burst of release.

"Marshall" Her body curled with her climax as she moaned out the rest of her desires in his arms.

"Fuck!" He growled, feeling his own release shot out from him and in to her.

Thank gob he can't get her pregnant, because that definitely got in deep. He gently fell on top of her, nuzzling in to her chest as he caught his breath and the water trickled over his back. No words were spoken as they both drank the air, gulping it down with each breath while their arms remained locked around each other. Marshall smiled at each time she inhaled, her breasts pushing against his chest in the most endearing way. He finally lifted his head a grinned up at her, stretching his neck and kissing his lips briefly.

"How you feeling now?" He asked. She nodded.

"Better" she smiled.

"Good, that's like the only reason we did this, right?" He replied sarcastically and rolling his eyes.

"Oh yeah, totally" she joked and kissed his nose. He chuckled and took a moment to pull out of her, his dick stuck with a thin layer of blood as the water washed it away. She whined and giggled to herself.

"Good thing we did this in the bath tub or else there would've been a bigger mess" she said.

"Yup, I'm so smart" he replied, smiling to show off his slightly blood stained fangs. She rolled her eyes.

"Yeah, whatever. You just couldn't keep your pants on when you were teasing me" she pointed out.

"No way, I had everything planned from the start" he lied, it was obvious.

"Uh-huh, sure" she leaned in and pressed a kiss to his cheek and mover her lips over to his ear.

"Thanks for the souvenirs" she whispered, referring to her three new bite marks. He kissed the one on her clavicle and licked up a drop of blood.

"No proble-"

"WHAT IN THE HAY HAY IS GOIN ON HERE!" Cake suddenly shrieked from the door frame.

"Cake-"

"GET OFF OF HER! I CANT BELIEVE THIS! IM GONNA STRING YOU UP BY YOUR BONES MARSHALL!" She shrieked and jumped at him. He floated out of the way and grabbed the ferocious cat before she landed in the water, her claws spread out and her eyes wild.

"Cake, calm down" Fionna urged as Marshall set her on the floor and got dressed. Thank you vampire super speed.

"WHAT DID HE DO TO YOU? WHY ARE YOU BLEEDING? DID HE BITE YOU?" She hissed. Fionna groaned and Marshall kissed to top of her head, fully dressed and already half way out the window.

"See you later, Fi" he winked and escaped out the window. All that was left of him was a chuckle and the bite marks across Fionna's wet and sweaty skin.

"THERE IS NO SEEING LATER!" Cake growled and jumped up to the window. Fionna giggled at her sisters futile attempt to get him back and punish him as she reminisced in the past hour or so.

"YOU COME BACK HERE IM NOT DONE WITH YOU!"

"MARSHALL!"