BBW36, you sound like a pretty cool wife that cares about your family. Your husband is lucky to have you.
LaFemme mentions communication. She's absolutely right. The problem is that, once again, it has to be both ways. It sounds like his wife has just decided that she's not interested in sex. You can't hold out for 3 months, not tell him why you don't want sex, break down and cry a couple times a year when he brings it up and not change anything, and expect that he's going to be happy with the situation. He sounds like a caring guy. If it was explained that she is exhausted much of the time, or simply has no desire to have sex, or it hurts (for whatever reason), and that she cares about him and his desires and his needs to be intimate with her, I think he would understand. It doesn't sound like she's done any of that. (littledumdum, if I'm wrong, please correct me.)
dolfette is absolutely right about mother nature limiting the size of the brood, so that she can provide adequately for the ones she has. I see where this fails in my job; moms are selfish and pump out half a dozen kids in 8 years, each from a different daddy, and leave the state to care for them. However, in being selfless for her children, she also needs to be selfless for her husband (somewhat). And I don't mean just putting out when he wants it, but acting like his mate and partner and addressing the issues.
A hormone imbalance was also mentioned. I work in the medical field and firmly believe in medicine. She has to want to be treated for it, though. I've read from other posters that said their wives had no interest in seeing a physician to make sure that the problem wasn't physical. I'm suspecting that she may balk.
dolfette, you make many intelligent posts. However, your first post about him only doing stuff to get something from her came across to me as talking about him like a typical man who only wants one thing. I'm guessing that's not what you intended, but that's how I read it. He shouldn't be made to feel bad for trying to lighten her work load and treat her well, hell even pamper her, in the hopes that she will want to be intimate with him. What else is he supposed to do? He's tried everything else, including talking it out, and isn't getting anywhere. My point was that if he wasn't helping her out, by cleaning the bathroom or whatever else he's doing around the house (apart from his full time job) there are other people that WOULD bash him because she's raising 2 kids and he's not helping her. He'd be wrong in someone's eyes, no matter what he did.
dolfette, it IS selfish of her to lose her sex drive and not want be at all interested in some type of a solution, or to even talk about it. You can't treat your partner that way and expect them to stay around and happy. It breeds contempt.
snbk, you make some very good suggestions. I hope they can use them.
helgaleena, the wife and her friends were talking about not giving sex to their spouses. Since he's not getting any, and her comment is that he wouldn't cheat, it IS demasculating, since she's portraying that she has him where she wants him. He works and provides, he's too loyal to cheat, and because of that, she doesn't have to put out and there are no consequences! His options are to put up with it her way, no matter what he wants, or to be a cheater. That actually doesn't show very much respect for him, in front of her friends.
Marraige is hard. No one realizes that until they are in it. It takes work, every day, on both parts. It sounds like he's trying everything he can, but she needs to at least make a little effort in the relationship.
Good luck, I really hope you can work this out.