This sounds a bit like the midlife crisis stories (which can occur at any age, IMO) where people get bored and look for new excitement, new fantasies, new secret relationships without much responsibility, etc. They engage their imagination intensely for a while because it just feels good, especially if it is reinforced/reciprocated. Then it dissipates and people move on (or blow their lives, but that was not the case here).

I was involved in quite a few of such relationships in my youth, with married men. Some never progressed beyond fantasizing and sexual tension, others became quite intense and engaging, even obsessive affairs. I kept in touch with some of those men over many years or reconnected, and we often discussed that past phase - it was interesting when people could be honest but disappointing when they couldn't. Why are you hesitant/afraid to confront the T, Nicole? Given that you do seem to have a desire to confront him? Do you still have feelings for him and maybe don't want to break the illusions/memories? In my case, I never felt I gained too much from the above discussions that happened later, not even from those that were sort of interesting. They mostly just confirmed what I already figured by myself about the nature of the relationships and the other person's motives, as well as my own motives back in the day.