I think in general women see sex as more emotional than men. Women are more attracted to the person, and men to the body. Not that it's always the case, or that men aren't attracted to the person, but in general the emphasis for them seems to be on the body.
For women, arousal is actually a part of the emotional part of the brain (from a Brain and Behavior class i had). For men, it can be purely a reflex (as I'm sure many a teenager has discovered). You can be PARALYZED, and still get an erection. So, for us ladies, emotions are a BIG part of sex, so we assume it is for guys too. But that's obviously not always the case.
When I get to know a guy, the better a person he is the more attractive he gets, and the worse a person he is, the uglier he gets. A guy could be model hot, and if he's an ass, I wouldn't touch him with a ten-foot pole.That doesn't seem to really be the case with men: a chick is hot if she's hot. She can be a total bitch and he'd still "do her." He might not stay till breakfast, but he's got no problem having sex with her.
Disclaimer: These are broad generalizations. As such, they're not applicable across the board, and I would say particularly here, from what i've read.
Now, on another note. I don't think you fucked up that bad. I think you did what any guy would do: you agreed with your wife. Unfortunately, that's not what she wanted. I would definitely do couseling, individual and couple. She probably has some body issues that she could use some help with.
Another thing is, maybe it wasn't the weight that turned you off, but HER obsession with it? I mean, if she's ALWAYS saying how fat and ugly she is, then that's not very attractive. If she ignored her weight and acted sexy (wearing sexy clothes and taking baths with you) it might never have become an issue. Just a thought.
