It is unnecessary and not important at all to tell your new partner how many men you've slept with... I'd probably be interested in knowing about his past experiences if he pronounced an ex's name when making love! lol!!! well seriously, I wouldn't tell him.
I tend to be a jealous person, and I know he has had a sexual past, but I really don't want to talk about it too much. Of course once in a while something will come up with a reference to the past, but I try not to do that.