> But what if her sex drive never ended, but another guy is
> benefiting from it? Don't think someone asked that yet.
Well, if the basic trust in gone, then what's left in a relationship? Can you trust your partner? Has he/she ever told a lie or how does he/she relate to lies in other circomstances?
My wife tells me that whe she had her spiral replaced, the sexdrive almost disapperared with the new spiral, apperantly because of the hormones. I can tell because she doesn't easily get arosed, she doesn't easily "get wet" and the climax isn't so great. Its the convenience of a safe contraseptive weighed against somewhat reduced sex.
Thats where this other dimention of the man's personality comes in. Every girl should be aware of that. The grown-up mature man is able to set aside, or postpone, his own immediate sexual desires to make sure his partner is well. If he can't do that, what are the chances he will be able to do that successfully it if she really gets pregnant and maybe find it difficult to have sex towards the end of the pregnancy? Just not to talk about what happens once the baby is born, and requires her attention 24/7? (I don't think he can)
On the other hand, I think that sex once a month is on the low side of whats normal. You could seriously concider finding out why. Maybe you should see a doctor or something? Just to be informed about possible causes. At some point I guess you have to find out if you're going to find a solution?