He revels a little.

Morty slowly opened his eyes and glanced up at the dark ceiling. “God, that was so good.” He sighed in pleasure.

“God that was so good.” Summer echoed, causing him to freeze in place, his eyes wide with fear. He listened for a moment, but all he could hear was her breathing deeply. “Mmm, Morty your cum is so tasty” She moaned again.

Morty slowly slipped to his knees, and gently lifted his head up over her bed, to glance at her still prone form. With a sigh of relief he quickly grabbed the device from her ear, and slipped out the door, before she could actually wake up. Closing his door behind him he thought for a moment just how amazing this experience had been.

His sister was moaning his name in her sleep. She was dreaming about him, and not the boy she was into. His plan was moving at a great clip, and it was going to be hard not to be inside her every night, but he had to be patient. He had come this far, and he needed to play the long game for this to work.

Summer and Morty were fraternal twins, born at the same time, with her being a little over an hour older than he was. Something she had used to consider herself the 'Big' sister. Normally neither of them did much for the other's birthday, usually little tokens of affection, and their parents never made it a big affair either. In fact recently, it seemed like they usually just gave them money, and said the words. Morty knew exactly what he wanted to get Summer this year. Something perverted but with a thin disguise.

As the week drifted by their birthday came, and once again their parents were off doing their grown up stuff. Morty was sitting in his computer chair, playing Borderlands 3, when someone knocked on his door. Pausing the game he turned toward the door and called out for them to enter.

Summer walked in and smiled shyly at him. “Hey bro, what cha doing?”

“Oh, hey Summer, just, playing some games.” He shrugged, trying to control the blush that was starting to form.

“Cool, I uh, I know we don't usually get each other gifts for our birthday, but I wanted to get you a thank you, for helping me out with my costume.” She smiled.

“Oh, gee Summer, that's really sweet of you.” Morty smiled surprised.

“I know you've been raving about that game you've been playing, so I got you some merch.” She smiled, pulling a box from behind her back, that Morty hadn't noticed.

Opening the box she pulled out a dark blue shirt, with the redheaded vault hunter Gaige. Gaige was Morty's favorite character from borderlands 2, and while not apart of the third game, that he was currently playing, he wasn't about to tell his sister that, or snub the awesome gift she had gotten him.

“That's awesome Summer, thank you so much.” He smiled from ear to ear, as he got up and accepted the package.

“I uh, I got you something too.” He said, gently putting the shirt down.

“Really?” Summer asked surprised and elated.