I’m in a messy situation with a girl who has a boyfriend and I don’t know what to do

I need outside perspective because I’m too emotionally involved.

There’s a girl I’m very close with. She has a boyfriend. Over time, our dynamic has become very flirtatious and physical. It started as jokes and tension, but it’s escalated.

We hold hands, sit very close, she initiates physical contact, and we’ve done sexual stuff over FaceTime (dancing in underwear, sending revealing pictures, watching porn together, etc.). She tells me not to tell her boyfriend. She’s also joked that I’m “trying to make her cheat,” but she actively participates and escalates things too.

There’s a lot of push-pull. She builds things up, then pulls back and goes back to normal with her boyfriend. The “almost cheating” energy seems to make it hotter for both of us. We both know it’s wrong, and that’s part of why it feels intense.

I’m attracted to her and I enjoy the attention and tension. But I also know if I were her boyfriend and she was doing this with another guy, I’d be furious.

Part of me wants this to lead somewhere. Part of me knows this isn’t healthy. I don’t know if she genuinely wants me or just likes the thrill of crossing lines without fully crossing them.

Am I being used for excitement? Is this something that ever ends well? And how do I handle this without blowing everything up

(Im best friends with the boyfriend, and the girl I knew the guy before the girl. Yes I’m a dick)

Thank you for reading.