Just idle curiosity, not wanting to change it.
DS (7month) has never once let go of the boob himself. DD was BF and she would always relax her mouth when she fell asleep feeding so the breast would fall out iyswim.
DS somehow manages to maintain suction even when asleep. Has done this often for a full nap (those early days when they fall asleep on your lap feeding and you daren't move an inch in case they wake up) and even for a good few hours at night - ie will fall asleep feeding, wake up 4hrs later and he is still asleep and attached!
Was wondering if he is some sort of freak how common this is?