First: Has she DESERVED the right to know such private things about you? If you feel that she hasn't, just tell her 'I don't know how you feel about that kind of thing, but for me it's a bit private. Maybe if I get to know you better first...' Integrity is manly.
And if you think she has deserved it...
If she asks about your first time (which sucked):
'A complete disaster. This girl actually had no clue about how to please a guy. Can you believe she actually BIT my boy parts? In fact, just thinking about it makes my nuts hurt...' Look pained at the memory, then look into her eyes, chuckle a bit and shake your head. Use the situation for bonding tighter with her.
If you're still a virgin: Just say that you're a virgin because you haven't met that special girl who could really get you fired up for sex. Make it sound as if your virginity is a personal choice you've made. Make her think: 'No other girl has measured up, and he's clearly not sure whether I am good enough.' Make her chase you!
I have to add that this whole "most girls just don't measure up"-routine works great if you use it when talking more generally about sex too... Used it on a girl online a few days ago, and now she's practically begging to be my FB. I didn't know it was so easy.
I just started reading about the whole gaming business a week ago, and boy are things rapidly changing in my life. I've just realized that I had a lot of the tools in my personality already, I just wasn't using them to build attraction.