My boyfriend chews with his mouth open. I have told him that's rude and gross, but he still does it. It is like he has no manners at all, and doesn't care that he is even doing it. No matter what is in his mouth food, gum, or etc... My son and I cann't stand to even eat with him anymore.

You have to eat with him and suffer, but
Your son cetainly does not have to.
If the worse come to the worse , just change
Boyfriends.

Tell him what you told us here.
You will stop eating with him if he continues. Old dogs can be taught new tricks. Just takes the right approach.

Have him go to the dentist, could he possibly have TMJ that prevents him from keeping his mouth closed during chewing?

Yes, TMJ is a possibility. I have that, and it can make it really hard to open or close my mouth at times.

Clough,

You must be aware of the ASSOCIATION:-

The TMJ Association - changing the face of TMJ
The TMJ Association is a patient based advocacy organization, whose mission is: to provide information on temporomandibular joint (jaw joint)...

The TMJ Association - changing the face of TMJ

Hmmm - that sounds really, really, really yucky. If it turns out to not be anything medical, maybe you can find a way to video him when he's eating without him knowing it, and make him watch himself, and the reactions of others around him? A little humility never hurt anyone. :}

I know a few people who keep their mouths open whilst eating.

They seem totally oblivious to it, when you tell them they just say " oh do i " and carry on.

I think it's pure habit, in their case.

Hopefully your boyfriends is not medical.

Maybe in casual conversation you could mention it to his Mum.. see if she say's " yes bless him he's always done that ever since he was little", in which case why didn't she correct him.

On the other hand she might say, " i don't know why he does that, he didn't do it when he was younger", in which case it has to be a more recent thing.

I'm betting he also makes that awful noise that goes with it... in which case, eat elsewhere or before he does.

Unless ofcoarse it's medical!!

Just kindly remind him every time he does it, help him become more aware of the behavior.

This is probably more a subconscience habit then anything else, but please verify it's not medical if that is suspected.

I often shake my leg and it drives my partner crazy. He started pointing out when I would do it and now I am more aware of the habit when I am near him because I know that he finds it bothersome.

If it's a bad habit and not something he cannot help, just tell him that it makes you lose your appetite so it's not negotiable if he wants to eat with you. Then if he does it, pick up your plate and leave the table.

This kind of behavior can very quickly erode physical attraction, and I don't think I could tolerate it in a boyfriend or husband. I wouldn't find them attractive any longer if they did stuff like that.

I must just be ruthless. Other posters are trying to excuse him. My knee jerk answer was "drop him".
That is so gross, so rude, and he is influencing your son. You have ask him to stop, he won't and he doesn't even care how it makes you feel. You don't have to settle for this obnoxious guy. If he had a medical problem with his jaw, I would think he would know it. Or if he gave a damn, he would follow it through and get it checked out. Drop him, he's gross.

Well, my boyfriend does the same thing and it goes through me like finger nails on a chalk board. I have asked him so many times to be more conscious of this and he just gets so mad at me. Today he flipped and said he is no longer eating with me. 28 years and no girlfriend ever told him about table manners? How can this be?

Either don't eat with him and never go out to dinner with him
Or this may or may not work
Start eating like he does and he may complain about it and you can say that's exactly how you look. It should only take a few times if he doesn't say anything within a couple days then its not worth doing anymore.

They say that it is a trait of highly driven successful people to chew with their mouths open. Maybe because nobody else can stand their chewing so they bury themselves in their work?