What do you believe is the appropriate age to lose your virginity?

Of course this is entirely circumstantial and personal. My sister is 19, almost 20, and still a virgin. We were discussing this fact and she feels like she’s rapidly approaching the zone of being “too old” to be a virgin. I’ve encouraged her to wait for the right guy, obviously. It’s a personal matter, but when do you think is the universal “right” age to become sexually active?