I'm not to piecing (yet), but do have a lot of road time with the infidelity, so here's my 2.5 cents:
-Yes, they do diminish over time, but you will have them pop up at the weirdest times, or when you are stressed or feeling insecure...it was important for W and I (after round 1 of mlc replay) that I tell her that I had a "trigger" so that she knew why I was acting the way I was. You might want to let him know, if you haven't already, that you probably will have triggers and that it doesn't mean the "end" or anything like that. Just be prepared for yourself and have a plan as to what you are going to do, be upfront with H without having to dig into "that" past, etc.
I am happy that you are where you are, good work!!
T^2
In the depths of winter, I finally learned that within me there lay an invincible summer. - Albert Camus
Uncertainty is the very condition which impels people to unfold their powers.-Eric Fromm