Its really a toss up for me. It sounds reasonable, but i'm fairly certain most women are offended by the idea. If she asked me to sign a pre-nup, it would trigger my wtf meter.
Ari Gold on pre-nups:
Ari: Have you ever heard of a fucking prenup?
Terrence: Oh, you have one?
Ari: I'd kill my wife before I got a divorce.