It's different in the eyes of the security services because of the potential for blackmail. A single guy picking up girls is not particularly blackmail-able. A gay man in a society that imprisons and chemically castrates gay people? That is someone who is trivially subject to blackmail.

Even to this day, I believe the security services will ask if you are homosexual and still in the closet, as you are keeping a secret from friends and family that could be used as leverage.