When someone (usually a male) conceals the fact that he or she is a virgin due to age and embarrassment
Person A: Man I had my first puss when I was like 12 hbu?
Person B (Closet Virgin): Yeah my first time was in high school with the really shy exchange student who only talked to me
Person A: Yeah? How was it?
Person B: Oh you know... really hot but awkward, like in books or movies