sex on first date depend on a lot of things, 1 is it you met the girl on the road talk to her, took her to your house and have sex with her. 2 either you saw her once exchange contacts like phone numbers and you called her on regular basis until the day you have sex with her?. well ! i had sex with a girl on first date but go no were, its ended the next morning. if you need a good relationship don't be in a rush to have sex, take your time and study the relationship you may found out thing you wouldn't have notice in a rush. but don't be too slow it may too dangerous.