1. The person has not yet engaged sex because he is so socially crippled that whenever he is around the opposite sex he begins to hiss and fart uncontrollably.
2. When the dudes are shy, it's considered really uncool for the girls to know. simply because of that, the girls are very easily frightened away.
Jomfru: Cause we're too shy the girls don't like us.
Somalian boy: Omg look at those Jomfru's they'll never get laid.