looking for a title

I'm looking for a straight manwha I read a long time ago
the story was the mc (guy) who moved and had a roommate but he didn't know that this roommate was his highschool bully (or something?) I can't remember clearly but I remember that she would make fun of him a lot until she sees him masturbating in the bathroom and realizes his dick is huge as hell
also this said guy likes someone else and I think she works at a convenience store but they're all classmates here, or ex classmates
said girl that he likes kisses him and I think the girl who bullies him finds out about it and is jealous

the cover of the manga was the girl who bullies him, she had long black hair and only wearing underwear in the cover. The mc has a really short black hair

also yeah it was porn, and I think it was painfully obviously supposed to be with how big the boobs were drawn

I apologize if the explanation is a bit confusing, but I just suddenly thought of this so if anyone knows what the title is please tell me