User post: Should I tell the new guy I'm dating about all my previous sex partners?

I just started dating this guy who I really like. Here's the thing; He has only been with one woman and I have been with 15+ guys. If this relationship is going to go anywhere, lying probably isn't what I want to do right? But, I know guys pretty well, and no matter how thoroughly I explain myself, he's going to see me as kind of a slut. This is how I see it anyway. Is it really necessary to tell the guy about who and how many. Isn't it a faux pas to talk about past relationships? This is weighing on me, and I'm not sure what to do.