Your sister

Carefully you entered your house and closed the door behind you, trying not to make any noise. You heard noise coming out of the living room, your mother must have been watching TV. Tiptoeing you walked through the entrance. You reached the stairs to the upper floor, where your room is. Slowly you placed one foot on the stairs and pushed yourself up. The next step followed and than the next. Only a very light creaking sound was revealing you.

"Nice ass, bro." You suddenly heard somebody saying from below as you had nearly reached the upper floor. You turned your head around with a shocked expression and saw somebody standing at the foot of the stairs. It was your sister Alison. She smiled at you.