Can you tell if a girl is a virgin or been with many guys when having sex, or is the tightness the same whether its the first time or many?

Virginity: There is no way to know if a man is a virgin. Not just from their anatomy. The same goes for a female. Not all females have hymens in place and with menstruation there is no guarantee that there weren't complications. Remember if you expect this of a female they have the right to expect it of you as well. That is the philosophy of this doctor in the U.S. All women treat with respect.