They both have "a" and a "c" in them too...
Sorry.... don't know why but this thread seriously brings out the wise ***** in me. I have deleated other comments but am just losing ground on self control.

I dated someone who I think really would fit the DSM requirements. I was peaceful and he was the psychopath.
We made it three years before he crossed my line. Perhaps it was because he was working very hard to have a relationship with me dispite himself.
I think part of why it worked for as long as it did (and Myer please feel free to add your view) was that I didn't react to him, we interacted. I refused to play games or get sucked in. If he went into drama, thrill seeking or being the hero I would just sit and let it pass. Even at my weakest moments I refused to let go of "me" which I think he did not expect and saw as a challenge. I know the thing he said to me most was that I was "a lot stronger than I appeared".
Our last date was his birthday. I brought him to his favorite place to eat and then we went for an evening walk in the park. We sat on a bench, under the stars in front of a beautiful fountian. Music from a nearby concert could be heard in the background. Yep... a fairy tale sort of night. I curled up next to him and gently laid my head in his lap. As he gently stroked my long hair he very "romantically" (and his tone of voice was seriously romantic...) said that he was just thinking... It would be so easy to snap my neck and he could be out of the country before my body was found and anyone went looking for him. I agreed that his statement was true, waited a moment, said I was cold and he drove me home, politely greeted my dad (who was not supposed to be there), kissed me and left.
At that point I became too worried that he was losing ground with his "inner struggles" and my luck sucks... So I left. And by left I mean dropped off the face of the earth left rather than just stopped returning calls.