You know all those fics where it is a Ds universe but Jim lied and said he was a dom, but really he was a sub and subs can't be in command without a dom? When I am reading them I can't help wondering why he didn't just say he was a switch, so I want a fic where he does say he say he that he is a switch, but someone finds out that he is a sub and blackmails him into sleeping with them.
Later Jim is just starting to feel safe again when he finds out he is pregnant. Male switches can't get pregnant though, so he leaves Starfleet to hide his pregnancy. Cue Spock (or Spock and Bones) who has a major crush on him trying to find out whats wrong and get his captain back.