Jo, it's totally fine You'll produce more so bub will still get heaps of colostrum after birth.

My toddler's still BF so he's getting all the colostrum now. He'll have to share soon! LOL

Lulu, I think, like most things, it'll only work if your body's ready to go anyway?? So a little bit of action from your DH probably won't do much. However if you're at high risk of preterm labour then you might want to avoid it. Like I said above, I'm still BF my toddler, so there's been heaps of nipple stimulation and I'm over 38w now...