Warnings: Stepcest, slight age gap, fingering, piv, thigh riding
Throughout high school you had been obsessed with Eren Yeager. He was tall, strong, handsome, and a few years older. When he graduated your sophomore year and went off to college far away, you figured that you would never see him again. He had never shown any interest in you, and you had never confessed to him, so it was just better to let things go.
After you graduated you decided to go to college in town so you could keep living with your mom so she wouldn’t be lonely. You’re pleased when she finally marries the guy she’s been seeing the last couple years. You didn’t exactly like him, but you didn’t dislike him either. Everything you knew about him your mom had told you. Your mother was his third wife. His first marriage had ended after a fight about how miserable their son was and she had left both of them. His second wife had died of cancer or some shit, you couldn’t remember, and you really didn’t care.
You knew he had a couple of kids. The younger one was away at college right now, and the other one, Zeke, was absolutely insufferable. Zeke was twenty two and couldn’t seem to get his shit together enough to move out even though he’d graduated both high school and college early. His mother apparently wanted nothing to do with him, so he clung to yours for dear life, which was obnoxious, but if it kept him from crying to you, you were fine with it.
When the holidays roll around, Grisha’s other son returns from his fancy college far away, it’s none other than Eren Yeager, and it’s his turn to be obsessed with you. He accompanies you everywhere you go, telling your parents that you were friends in high school and need time to reconnect, but you quickly notice the way he keeps a protective hand just a little too low on your back when you’re out. The way boys that were usually all over you skirt away when Eren looks at them.
Eren’s tall and nothing but hardened muscle, but his skin is soft, and his hair is silky as it brushes against you when he stoops down to kiss your cheek, making you blush. When other boys flirt with you, his arm around you tightens and he snaps at the poor man foolish enough to cross him.
The possessiveness builds and builds until he can’t take it anymore and finds himself standing outside your open door long after your parents have gone to bed, leaning on the doorframe, observing you. He knocks gently to draw your attention and asks if he can spend some more time with his little sister before he has to leave again. Naturally you let him come in and sit on your bed, not minding how he closes the door behind him, or how he watches you strip off your day clothes and riffle through your drawers for a fresh set of pajamas.
You notice how close he gets when he stands behind you, pressing his warm body against your back and running his long fingers down your bare side, kissing your shoulder and asking if you still have that silly little crush on him. Your cheeks heat up and you rest your head against his chest, looking up at him and confirming his suspicions, allowing him to kiss you on the lips, the way you had both wanted to for so, so long.
He flops onto your bed and opens his arms wide, urging you to join him, and you do, falling into his arms and giggling when he squeezes you against his chest. His laugh is a warm hum as he watches you rest your legs on either side of his thigh, playfully rutting your hips against it once to gauge his reaction. When he doesn't chastise you, you do it again, this time your clit catches deliciously on the material of your panties and you keen, burying your face into his chest.
Eren holds you tight against him as your hips work against his thigh, drawing soft sounds from your lips, Lips he so badly wants to taste, so he releases you and cranes down to peck at your lips, letting out a pleased groan when you deepen the kiss and chase after his lips greedily. The flannel of his pants rubs you raw through your panties but it feels too good to stop, so you don’t, whining in pain and pleasure as you reach your release in Eren’s arms.
He unclasps your bra and slides it off you before rolling over you, covering your body with his as he kisses and nips at the softest parts of your skin, rolling his warm tongue over them after to soothe the sharp ache his teeth leave behind. Eren shoves his hand into your panties and moans when he feels how wet you are for him as he teases your entrance. He silences your moans with his mouth when two of his fingers push into you. He whispers about needing to stay quiet because mom and dad would be so angry if they caught him touching his sweet little step-sister like this.
He pulls your panties down your legs and rubs his cock through your folds, looking at you, waiting for you to tell him to leave, to get out and not come back, but you don’t. You just look up at him with sleepy eyes and spread yourself wider for him with your fingers. Eren apologizes softly as he shoves his cock to the hilt into your pretty pussy, because he knows it’s uncomfortable, but he’s waited so, so long to have you and here you are, right in front of him.
Eren’s greedy, and possessive but he’s not a mean brother, so he praises how well you take him and how sweet you are for him as you claw at his back and mewel under him. His kisses soften as his thrusts get harsher. He growls something about your needy cunt being his and only his to fuck, and you mindlessly agree as he toys with your nipples, urging you to cum before him. And you do, locking your ankles behind his back, trapping him inside you as he cums, filling your little cunt and marking it as his.
You lay limply on the mattress as you come down from your orgasam, watching as Eren gets up, tucks himself back into his sleep pants and leaves the room. You had expected him to just go to bed, but he returns with a warm rag and gently cleans you up before dressing you and tucking you into bed. He sits down and kisses your forehead and rests his hand on yours through the blanket, promising to spend some more time with you before he leaves in a couple of days.