"...being unfaithful seems like way, way too much work and mental baggage."

Amen. My thought has always been two things:

- keeping one woman happy is difficult enough such that you only want one

- if you really decide to go down that path, then the relationship you're in is done.

It has been an understanding I've had with every girlfriend and even my wife - if either one of us really feels the need to go outside the relationship, then the relationship is done.

I have been really fortunate in the sense that I have no knowledge of any of my girlfriends having cheated on me. And I have never gone outside my relationship. Once someone did date someone while we were "on a break" to borrow the Friends term - and that was how the break turned permanent.

I have been propositioned a few times (note: not in a long time anymore) so its not like I didn't have the opportunity. It really was thrilling that someone else found me to be sex material, but like you I've seen how that ends and so I thank them for the complement but refuse.

I just say nice job sticking to your morals and ethics. Its much harder to back away from that door once opened than step through.