In a fit of anger and frustration, Checkpoint15's step-sister storms into her brother's room, slamming the door behind her. He looks up from his bed, startled. She starts to yell at him, but her words trail off as she notices the bulge in his pants. She hesitates, then crosses the room and straddles him on the bed. He reaches up, pulling her face down to his, kissing her roughly. She grinds against him, feeling his hard cock through their clothes. He reaches down, pushing her skirt up and pulling her panties aside, slipping a finger into her wet pussy. She moans, riding his hand as he finger-fucks her, bringing her to a climax that leaves her breathless.