My daughter's boyfriend came to dinner last evening. His table manners are appalling! Elbows on the table, chewing with mouth open and waving and pointing with his irons! He is a quite well spoken chap and when away from the table, well mannered. She is very fussy and yet didn't seem to notice.
I have just witnessed the worst manners ever. I took GD to McDs and four females were eating at a table near us, when they were leaving they threw the remainder of their meals and the condiments over the people at the next table. The offenders, all wearing pyjamas and effing and blinding, left the building and got in a taxi. Never in my 72 years have I seen anything as vile as this, they made pond life look intelligent.
The only thing that would really bother me is the eating with mouth open. Yuck! However, I wouldn't say anything to bf (boyfriend) about it or to dd either. She must be aware of it, and if it bothers her, she'll deal with it, eventually. If it doesn't, it doesn't - not much you can do about that. For now, maybe try getting together with them for events that don't involve meals? Otherwise, try not to sit opposite him, LOL!