Gentlemen,

here is the loop

  1. You are told of the previous asshole boyfriend who is supposedly insane
  2. You enter the relationship
  3. It is revealed she is lying about something, something big
  4. You get angry about it
  5. She skips to the next relationship she has in her back pocket and has been cooking on the backburner
  6. The betrayal causes you to say shit, or phone more than is appropriate, or throw a coffee cup etc.
  7. Your behavior at STEP 6 is used as proof of STEP 1 her new boyfriend is now experiencing

It is bait that is used to make you react in anger. If you react in anger in any way, they use that as proof to their friends you are insane.