Long Vent - Coworker Kissed Me

I didn’t want to post this originally but I need to get this off my chest. I’ve been recently told it’s very likely I have OCD by a therapy service, and one thing that really bothers me is guilt and shame after doing something even slightly wrong. In this case I think I did something truly awful and I don’t know what to do. I haven’t really eaten today — I should be studying for my exam tomorrow but I can’t get this off my mind. The guilt feels like I’ve murdered someone. I joined a new job a few months ago and have been pretty quiet there since, but recently decided to try to make some friends there and show my actual personality. I was invited to a pub with a few of my other coworkers but only 4 of us showed up — a girl I’m friendly with, a guy I’m friendly with, and a guy I don’t know too well whose girlfriend (who we also work with) has recently been promoted to our team leader. It gets bad here. We’ve all been drinking for a while and I’m starting to feel drunk, along with the other girl who, due to other reasons, ended up feeling very sick. They were all openly talking about sex at one point and the guy I don’t know well — who I’ll refer to as M — mentioned at some point that he was in an open relationship with his girlfriend. I remember him saying most physical things were fine as long as they talked about it, but romantic feelings were off the table. I should add I had no intentions romantically towards M. No attraction there, no feelings. I actually thought he might dislike me. It gets worse. He told me the other guy we were out with liked me, but was being respectful about it. He then added that he was also attracted to me but that was a conversation that would be had with his girlfriend. I am ridiculously oblivious and don’t process things properly when I’ve had alcohol just like any other drunk person, so thought he was just saying it in passing to demonstrate his point about the other guy’s respect towards me. I’ll admit I was flattered by that but still had no romantic feelings and didn’t reciprocate the attraction (for some reason I felt similarly to the way you do when a friend jokingly calls you sexy or something). It gets even worse. My female friend is violently ill and I go to look after her when M texts me saying he wants us to come out of the bathroom so we can leave. I thought he and the other guy were having some sort of argument. He texted telling me to just act drunker than I was and, I quite literally quote, “be all over him like I couldn’t get home without his help”. I did act a little bit drunker when I went out to update them but was against the idea of being ‘all over him’ so just spoke to him like I was drunker than I was. For some reason, and again I say I don’t read things properly when drunk, I didn’t think this was strange. Then we get to the train station to go home — the first guy who apparently likes me?? is with our friend. It’s me and M at this point and he keeps asking me if I’m alright. I tell him yes, which is true. I was drunker than I realised (the situation with our friend and being in the cold made me feel more sober than I actually was). He ended up offering me his hand to hold and I thought he was just trying to be comforting for some reason so I took it. This is the part I really regret. He put his finger under my chin and leaned in a bit. I didn’t process what was happening and turned my head. I then thought ‘was he trying to kiss me?’ and for some reason made the stupid, drunk decision to turn back and try to figure out if that was what was happening. I don’t remember if I leaned into it a bit but he went for it again and kissed me. I should add that, were I sober, and (I sincerely hope but ocd is kicking my ass) had he asked me and had I actually had the time to process it, it wouldn’t have happened. It lasted about a second, maybe less, before I pulled away. I told him he should speak to his girlfriend and I felt guilty. He agreed that he would (which, having spoken to him today, he told me he has and she’s okay). Then he tried to kiss me twice more, both of which I dodged. He was respectful here and said that was fine. He later said repeatedly something flirtatious like “you know what you’ve done” and that made me uncomfortable so I kind of awkwardly laughed it off. We’ve spoken this morning, I’ve confirmed he’s spoken with his girlfriend and I’ve firmly said I’m not looking for more than friendship with anyone, especially not at work. He agreed but keeps insinuating I was being purposely flirtatious throughout the night (which I wasn’t, that was never my intention. He also keeps joking about it happening again and that it’s ‘funny he kissed me before the other guy considering the effort he put in’. I should say that he asked me if it was consensual this morning and I answered that it wasn’t non-consensual if that makes sense, but that I didn’t process it as it was happening. I was quite shocked. I like neither M nor the first guy romantically. I feel awful about what happened and my part in it. I should’ve pulled away. I have to go into work this weekend, to see both people in the relationship and I honestly don’t know what to do. I like and respect his girlfriend a lot in the time I’ve known her. Even though I didn’t plan anything or have any intentions I feel like I’ve stabbed her in the back. I’m worrying he’s told her I was flirting or reciprocated his attention (now sober I’ve put all the pieces together somewhat) and was the one to initiate it. Or what if my other coworkers find out and think I’m trying to be a homewrecker?? That’s a selfish question in itself, I shouldn’t be concerned about myself. I just don’t know what to do. I know I’m in the wrong, and I don’t expect anyone to say differently, but I just need to talk about it before I go insane. I’ve never been this physically affected by my OCD before. I can feel it everywhere in my body. I’m seriously considering leaving it for a bit before quitting when I get back from uni. If you read this or scrolled to the end, thank you. I’m sorry I’m such a mess. I just need to make it through my exam, and then the weekend, and I might start to feel better.