Well met an old friend recently use to date in high school been thinking of him a lot how to tell my husband?

Tell him what?

Aw geez,its kind of normal seeing an old friend/ flame, and think about them a lot afterward. What is there to tell? Are you going to be in touch often? If not just say you saw and old flame If you intend to keep in touch its better coming from you than finding out after the fact. What's the big deal, is he a jealous boob who doesn't understand running into past high school mates, or exes?

Easy. You don't say anything. Some things in life are better unsaid. Unless, he ask you first. Why get him all riled up over your thoughts which are normal. I sometimes find my thoughts drifting to "what if?" I had married her or not married her? How would my life be? Best way to start a fight is to say you notice someone and think about someone other than the person you chose to spend you life with. Thing is you made the right choice. Whose to say? You judge yourself when you second guess. Its seems the grass on the other side looks green from a distance. But if you water your grass and treat it w/ some love fertilizer. It is just as green.