When a female virgin first has
vaginal intercourse, or some object is inserted into the vagina, causing the hymen to rupture, resulting in bleeding. The term "cherry" is used to refer to the red of the resulting blood. However, not all women are born with a hymen, and certain hard physical
activities may cause the hymen to tear. Though no surgery can restore
virginity (i.e. you can't 'un-have' sex) there is a procedure to restore the hymen to its original state.