I went to the room where he slept and I wanted to see his ass

My new roommate came out too often from his room in his underwear, now I know he was trying to provoke me. I loved how tight they looked, it must have a great ass and I needed to see it. One afternoon, while taking a nap, I slipped into his room and tried to pull his underpants down, but then he caught me and urged me to finish taking them down. I was looking forward to him fucking him.