It sounds as though you love him. Then you must know how dehumanizing pity sex, hand jobs, or whatever once weekly mechanical relief you offer to assist with will be.

I feel that open relationships, cheating, and anything which smells like infidelity is a horrid risk for any family with small kids, but almost any of these alternatives is better than submitting to an act which disgusts you and humiliates him.

I want you to spend the next 48 hours imagining him with a willing partner who finds him appealing and enjoys pleasing him. All the things: his elation at feeling wanted again, her merrily blowing him, him going down on her for an hour. I want you to consider what he actually needs and deserves, which is a partner who enjoys him. If you are unable or unwilling, but wish to keep him around as co-parent, think about what his life is like, how he feels about being rejected and barely tolerated by the woman he loves the most.

If you are still unable to muster some desire to enjoy him, let him have a few hours outside the relationship here and there.

I'm deeply sorry that the hormones that are likely driving your response are wonky; I loved pregnancy and nursing and felt so desperately horny and driven to bond with my husband that I darn near ran him off. It was bliss for me, and I hate that you aren't enjoying that. But I can't help but remind you that your husband is not suffering yo he illness, and if he's a good guy and a great father and husband, you cannot in good concious expect him to feel the disgust towards sex that you feel. He's human, and deserving of respect and mutual appreciation.

Either find a way to enjoy him, or offer him a few hours to share lust and sex with another.