Hmmm, for once i disagree with Ethel :(
I think a guy should pay a lot of detail into the sexual exploits of his woman to be.
What she has got up to in her past, shows what the woman is like in general.
Some examples :-
She sleeps around a lot - has no respect for anyone or anything and thinks the world should revolve around them.
She has lots of one night stands - needs to feel wanted.
She wont have sex with you - she has been a sla88er in the past, and now is taking it out on you
I could go on all night, but had better not...