Cheating OCD making opposite gender friendships impossible
So I've been in therapy for about a year now, and while I've made progress in a lot of ways, my cheating theme has been unable to beat. Literally every time I (straight/ace woman) interact with a man, I overthink it for days, wondering if I liked the attention or wanted to cheat. Too boot, I'm socially inept and have had times where men were flirting with me without me realizing, so I feel like I can never trust my gut.
This has been particularly hard when it comes to my friendships/coworker relationships with men. I'm an engineer and I'm in a run club with mostly male members, so most of the people I talk to consistently are men, though I do have plenty of girlfriends too. It's the same for my partner of 1.5 years—he's a nurse so most of his friends have historically been women. Neither of us have had a problem with this arrangement, but I freak the fuck out any time I have to be around men. For example, I have an old college friend (we'll call him K) who lives in another state, and he came to town to watch his best friend (who's in my run club) run a race. Boyfriend, K, and I all got dinner together, then K and I went to watch the race. I invited my boyfriend, but he hates sports so he declined the invite lol. I honestly had a fun time catching up with K as we rarely see each other anymore, and we've been good friends even when both of us were single. He's never given me a reason not to trust him, but the type of dating advice I see online is constantly reiterating that opposite sex friendships are impossible. The whole time we hung out, all I could think was "what if he secretly likes me and wants my relationship to fail? Is he standing too close? Is he making too much eye contact? Do other people here think we're a couple? Am I flirting?". When K and I were walking back to our cars, he even made a comment about how he was glad we managed to stay friends even after I got a boyfriend. Initially, I just took that as a nice sentiment, but then I got this crippling fear that he was actually trying to flirt by saying that. It's genuinely exhausting. I don't want to cut off old friendships just because of my anxiety, but I'm starting to wonder if it's even worth it. Has anyone been through something like this? Am I just being naive in thinking men and women can truly just be friends?