re: Does it matter if someone you want to marry is a virgin or not?
I would say share utna karo jitni ki zaroorat hai. Have you been in relationship before ? Yes . Who was she? Where is she? how did it happen? do you still talk to her? How long did it go? Do you still think about her? Do you have her pics? Was she pretty? etc etc… do not go into all these details. The more you dig, the more info you want to have, the more they will bother you in future. He was in relationship, he accepted. that should be enough. your decision should base on this one reality.
One correction in your post. Not sharing is not same as lying. they are two diff. things.