Does your partner's sexual history bother you?

I was just wondering whether the number of partners that the person you’re with has had affects how you feel about him or her. Since I’m still young and have a “number” of zero, knowing that a guy I’m interested in has been with quite a few girls really throws me off. Am I the only one? Should someone’s sexual history have a sway on how you view them or whether or not you want to get involved?