Actually, this is going to sound bad, but here's a secret. I think after everything my husband has done I'm entitled to this....
When my husband accuses me of having "secrets" or having had more "romance" during the separation/divorce than actually happened, I'll sometimes just smile a little wickedly (like I do have secrets) and say, "Oh, of course not. I'm an angel." In all honesty, over time, he knows everything and nothing ever really happened, but he happens to think there was more and what I've learned is...
Never put all your cards on the table. Even if nothing happened, don't let them know that! Hold onto those trump cards... or at least the appearance of holding trump cards!!!
There is no arriving, ever. It is all a continual becoming.