Is true that when you lose our virginity your body changes?

There may be: Some tearing of the hymen but there aren't really any major changes that happen to the male or the female body related to having had an episode of vaginal intercourse. If the female becomes pregnant - there would be many bodily changes.

Sexuality: There is nothing that changes in the body when one becomes sexual. Some girls still have their hymen and this can tear. But, other than that there is no way to tell if one is sexual or not by observation.