When your milk lets down, you get flooded with hormones that make you feel relaxed, peaceful and blissed out. I loved it! Babies who are actively nursing suckle in a way that’s not (as far as I know) a typical way a sexual partner would pleasure them. You’d have to look up a cutaway graphic that shows the process. Babies don’t suck the nipple. The nipple is drawn quite far into the back of their mouth. Mom typically doesn’t feel much nipple sensation while it’s going on. I do miss it.