In Bones' defense, I thought the punchline was fine -- and funny. 
From my experience, a bipolar person will be a completely different person when she's in the manic state than when she's in the depressed state. It's not the extreme of an MPD, but the personality and behaviors will be different enough to be noticeable.

From my experience, a bipolar person will be a completely different person when she's in the manic state than when she's in the depressed state. It's not the extreme of an MPD, but the personality and behaviors will be different enough to be noticeable.
If the only way you can fully understand a character is by knowing who they boff then you are a very sad person. Who they sleep with shouldn't matter.
That has to be one of the dumbest things I've ever seen typed. Why the hell does it matter? Or do you want it to be true so you can get your rocks off at the thought of her with herself or another woman? 