How are you getting him off the nipple? It might not help but if you're just pulling straight off, try just putting a bit of pressure on the side of your nipple so the suction releases but the nipple is still in his mouth. Then if he doesn't stir you can take it out slowly.
Sounds like he's just using your nipple to comfort like a dummy rather than feeding at end of feed. My baby feeds for half hour and then let's go but my son would of stayed on forever if I let him 😅 but I do use a dummy with my daughter didn't with my son but use your pinky finger and just release his suction and he should hopefully stay asleep
I do what Steph has described. I make sure she is asleep, press a little on the side of my nipple to release the suction and really slowly and gently pull it out of her mouth and she stays asleep. If she wakes up, I pop it back in and try again a few mins later
@klaudie same, I gently pull my boob away whilst patting bum