I think only if one or the other doesn't have a very stable ego. I know in my own experience it hasn't mattered one bit -- my first husband and I were both virgins when we met, but it didn't stop him from later deciding that I must be eyeing every male in town just because he had a bad self-esteem. My current husband knows I'm not a virgin, obviously, since I have a son that's not biologically his, and he has four children from two previous marriages. However, it's this second marriage that has worked out very well, and where there is trust and happiness. I can see where someone wouldn't want to find out that their future wife/husband had slept with half the town, but in many cultures it doesn't seem to matter if there has been a previous lover as long as they are truly in the past. I know there are some cultures where this is considered unacceptable, but even then it seems like people should be able to acknowledge that their intended is human, and all humans learn through experience and mistakes.