serious help, fb smacks his food

GUYS my boyfriend is such an unattractive eater. He is so so loud and obnoxious when it comes to eating. He says he’s a mouth breather and it’s hard for him when I let him know it’s quiet bothersome. Plus he claims he cuts his mouth all up when he chews with it shut. I’ve told him if I have to deal with him smacking his food all obnoxiously, he has to deal with me getting irritated... sorry not sorry, it’s disgusting and so unattractive! It puts me in an irritable mood, call me dramatic lol the thing is, he knows it’s annoying but literally has no interest in changing or trying to quiet down. I’ve tried smacking my food all obnoxiously back but it doesn’t even phase him! That’s the worst part. I’m at such a loss, it’s so embarrassing around friends and family. What are your guys thoughts on this?