My (30f) bf (30m) likes going to high end restaurants but doesn’t know how to act and it’s embarrassed

My bf makes a good salary, around $350k a year as such he fancies high end restaurants however whenever we go We get super embarrassed in addition he acts.

We went to a Michelin star fine dining restaurant that had a set menu. He asked the waiter in case he could tweak some of the recipes on there and asked the chef to make his meals extra spicy. The cashier responded back saying that they will don’t tweak their food and gave him a part of chilli flakes.

We go to a fine eating Koran bbq place where we got to bbq our own meats. He takes the medial side dishes such as corn, jalapeño peppers, white rice, spargelkohl, raw onions and blends it up in the tin tray that the meat came in and puts soy sauce and ketchup in it and lets it cook on the bbq where the meat is supposed to cook. He then proceeds to offer his mixed up gunk to everyone throughout the table (mind you this really is something that a 5 yr old would make).

Several us went to a high high high end steakhouse and everybody ordered their own entrees. Whenever he got his plate he started to chop up his food and starts spoon feeling his food to everybody around the table.

Personally i think so embarrassed that he doesn’t have any table manners plus idk how to confront a grown man about this.

TLDR: My (30f) bf (30m) likes going to luxury restaurants but doesn’t learn how to act and it’s ashamed