I think you are missing something. (I see it in the comments too). It's not about the sex. It's that she will give him no love...

Men marry for love, not sex. Sex is transient. Lonliness hurts and hurts. Men will do anything for love and almost all marriage vows mention love, but not sex. Sex is simply a hormonal urge that can be satisfied in different ways. Love is another thing. You should know that. The problem is as you say, women move their love to their children. It's not about sex. She refuses to give him love. It is common for women to do that (and explained by socio-biology).

My sister helps battered women and she can't understand that when he is arrested and asked why he hit her, he means exactly what he says when he says "he just wants her to love him". She swore to but decided, no, she wanted to love her children instead and sorry, but she doesn't care about him... oh, but he can pay for raising them.

... And for the folks below, I do almost all the house work. Her back is a problem, I admit but she could do more... cuz she will do almost anything for her kids. I also always took them out on Sat and Sun when they were very young to give her a break ... until they were old enough to be interesting and then she took over and basically turned them against me. Luckily for me, when the kids got older, they mostly figured out what was going on.

All I wanted was love. I thought that all people were naturally loving. Just treat them well, love them, nurture them and they will naturlaly love you. I was wrong.

This is very very common. She should give him a divorse because she doen't love him. I bet that she can't say that she loves him... and I doubt that she can touch him. He's dying.