First off, I have no idea how many women I have slept with (not SP's either)
I tried recalling recently and couldn't remember half of their names even. (Yeah, I have had a few one night stands.) So, it would be like, oh yeah, there was that red headed chick, then the chick who lived over the store on Younge Street, blah blah blah.
I never ask a woman how many men she has slept with. I consider it useless information.
If a chick asks me, I lie as bootycall suggested.
Pick a number you won't forget, because odds are you will be asked again.
8, eight is a good number. Of course if you are 45 years old and have never been married, that may be a little too low.
You have to use your judgement on it I suppose.
But lying in this case is probably the best course of action.