The thing that most warms my heart and hardens it is that while I was happily married to my wife I met that "other" at work while I was still happily married.
Time went by and I started to have feelings for this other woman and I decided I needed to put a stop to it... I needed to cut ties. It wasn't that hard to not act impulsively since I lived several hundred miles from her (we basically teleconferenced daily, but only met in person ~ once yearly), but I recognized it as a potential issue. So I started looking for a new job.
I contacted a former coworker who'd been begging me every 3-4 months to come work for him and asked him if he still had a job available. He did and I took it more of less on the spot. I gave my notice.
Then I immediately had to do a short-notice business trip with her, my boss, and my subordinate to train up my replacement (but my replacement was a team of 4 guys at a Mexican firm). As soon as we got in to the hotel we reported in to the group-slack what room we were in so we could coordinate a meetup.
Not five minutes later she was at my door and she gave me a big "I'll miss you" hug. Then she looked up at me, I looked down at her, and she kissed me in a way my wife hadn't in years. As soon as I registered what was happening I pushed her off and told her no.
This is getting way too long, but the TLDR of the rest of the week was: we spent every night talking, but no more touching. She wished she'd met me a year earlier because she liked me way more than the guy she married. I didn't admit it, but I felt the same way (mostly because I was familiar with the concept of "limerence"), except I'd been married more like 4-5 years at that point.
We agreed it'd go no further, that we both believed in marriage, and that we'd limit all future communications to business-only (no more sharing jokes/memes/etc no more fraternizing... just business). And we succeeded.
In our entire relationship this was the only thing I didn't share with my ex-wife, because I didn't want to hurt her (even though she basically did the same to me, but without the resistance/dedication a few years later, which led to our divorce).
Point being... I know I'm theoretically capable of still attracting people I'm also attracted to, but at what point do I stop feel like it's cheating? A friend of a friend (that I found physically attractive, if not mentally) basically flat out told me she wanted to fuck a few weeks ago and I turned her down because I can still feel the absence of my wedding ring on my finger... 16 months after taking it off.