Would a guy know when a girl pre came?

A girl does not have pre-ejaculate, only males do. The pre-ejaculate the males experience is when the tip of their penis leaks fluids when they are sexually aroused by the do not fully have an orgasm or ejaculate. Females produce a lubrication to prepare the vagina for the entry of the penis. This keeps the penis from rubbing against her vaginal wall and causing friction or abrasions.