Teeth getting in the way

When I ANR with my partner his teeth can hurt me, how do I make this easier obviously when I breastfed my children there were no Teath. Also I'm struggling to get my partner to latch properly is there any advice that you can give please? What is the perfect latch for adult nursing relationship to get it right and produce the milk properly, otherwise he will keep doing it wrong and it won't work, there is milk in my boobs and it sprays everywhere but when he suckles to get it very little comes out so are we doing something wrong, any advice would be most appreciated Ellie