DVRT-058 My step-sister doesn't normally see me as a man, but she shows me her tight ass! I can't resist and immediately shove my big dick in!

My parents remarried and I suddenly had a new step-sister. I grew up in a household of men, so I'm nervous every day about how to interact with her. My step-sister has no way of knowing how I feel, and she obviously doesn't see me as a man. She keeps a ridiculously close distance from me, exposing her indecent body parts without any warning, which is unbearable. One day, she puts on some skin-tight clothes in front of me, showing off the extremely revealing curves of her buttocks...