Is this normal to have thoughts about someone like this

(i’m a girl) So there’s this girl at work who i’ve spoken to a few times, and before i wasn’t super interested in her, mostly as a friend, but for a while she started to act like i didn’t exist. That was when i started getting weird possessive thoughts about her, like hurting her during intimacy or tying her up in enclosed places, and in the thoughts she’d be enjoying it sometimes and sometimes not. I also have ocd, so sometimes i do get really bad thoughts about her that i try to ignore, but the general ones i do enjoy. But i don’t feel any romantic attraction to her, and get envious of people around her talking to her. I want to make her feel pathetic in a good way, idk.