A couple things about lactation for MILK:

The first six weeks or so, milk goes EVERYWHERE. The baby cries? Milk falls out. The shower starts? Milk falls out. Funny commercial? Shirt drenched. It takes a while for the "let down reflex" to get the hang of only letting go when the baby is nursing. So MILK shouldn't worry, there will be milk. However! A few points about the process of nursing, that he should know:

Because of the whole let down reflex situation, some women can, at least initially, feel a little out of control of their bodies. If my son cried in the middle of the night when I was asleep, milk would pour out and I'd be lying in a puddle. If he's sensitive and more attuned to her needing some reassurance that this new part of her, "wife as mom," is sexy too, that might go a very long way towards making his lactation fetish fun for her. But there's more:

Women produce milk based on how much they're being suckled. At the very beginning after the baby comes (which is when any leaking collostrum changes to actual milk) his "nursing" in addition to the baby could in fact help her milk come in. He should realize, though, that she may be hesitant just then specifically because he'd be inserting himself between her and the baby at a very fragile bonding time, and as if that's not enough, also that early on women's nipples get cracked and bleed—fine for the baby, sharp stabbing pain for mom, and kinda not so great for sex unless he's also into blood. Also, once her milk is in, she gets into a pattern of when she's "full" and knows the baby needs to nurse. If feeding him is inserted into this pattern, it will at times be physically uncomfortable for her (though if she's pumping to go back to work, that can also be of benefit, practicality speaking). Full breasts hurt.

At the very end of when she's nursing that may be the best time logistically to really explore his fetish. As the baby begins to take food, he can keep her lactation going (just in case the baby gets a cold for example, when nursing is better), and it wouldn't presumably be problematic for her to keep going in an established pattern.

So to summarize, from a woman's benefit perspective:

· help her get used to "moms are sexy"
· possibly help her if she feels her milk production is inadequate
· help her produce excess so that she can pump more
· extend her milk production when the baby is tapering off

But the last thing he should know: Sometimes the let down reflex just isn't OK with the situation. I could never let down for that damned pump! I could watch my baby, record his cries, watch sad movies... nothing. Couldn't fool the girls, who might have well as yelled, "That's not a baby!" It's quite possible that she just won't be able to let down for him, in which case suckling her could be painful for her.

Offering Lactation Delights; Babies All Gone