Bored and horny, I invite my stepsister's friend over for a 'study session.' We start innocently, but soon enough, clothes are off and my cock is disappearing into her eager mouth. Just as she's taking me deep, my stepsister walks in, catching us in the act. Instead of freaking out, she joins in, her big tits bouncing as she takes turns sucking my cock with her friend. I can't hold back, and soon I'm exploding in their mouths, my cum dripping down their chins.