Is it a good idea to tell ur wife about ur past ?

If she asks, then tell.

I don't see any reason to hide anything, because it makes you who you are, especially if you were in a long term relationship.

If the thought of being with a nother person bothers someone...they should sort this stuff out before they get married. Because afterwards, it's really silly to ask and then expect.

Btw, my husband and I talked about this before AND after we got married and we have NEVER fought about these things.

Btw 2, I take a different approach to physical affairs and "crossing the limits." but that's a different discussion :)