Why invite him if she was going to embarrass the hell out of him. Maybe she was hoping he would pick up the tab and when he did not, she made him pay for himself, regardless of the situation, I'd be having to chat with her.

Your girlfriend has shown her true colours. She, as an adult, knows that since she invited you SHE pays. What her mother ordered is immaterial. The bad news is she's used to taking advantage of your generosity. Don't be a doormat! The good news is she's only your girlfriend. I wouldn't marry this woman.

That's odd. Why invite him if you're only excluding him? She should had just invited her mom, aunt, uncle and best friend if she wnated to treat them without making OP feel excluded. And saying "we're not rich" but ending up paying 300 euros but couldn't pay for a 30 euro dish for your bf? Also of anybody listened to the full story what does OP mean when talking about the meat the mom ordered "700 g"? Is it like grams? Because wow, that's almost 1kg. Who can eat that much meat in one sitting? 😅 Personally, I think the girlfriend is in the wrong, and OP's feelings are valid. I just didn't like how he complained and got angry when his gf's mom ordered the pricey meat/dish, saying how her meal made the bill jump. If the daughter was okay with her mom ordering anything and willing to pay for it then that's not OP's place to complain about it since in the first place he wasn't the one treating the people. Also even if the bill tirned out to be 200 euros if the mom didn't order the expensive meal, maybe his gf still wouldn't pay for him if he thinks that a smaller bill would have affected her decision.

The mother should have paid for her meal nta

Awesome! She established the precedent where you're only paying for yourself on dates.

Is this a regular thing or a one off. If it is a one off, you need to talk to your girlfriend and say what happened was not okay. She needs to know she stepped out of line. This is very odd.

NTA, if the bill was too much, she shouldve asked to split the bill. fine, maybe cover her friend since apparently she owed her, but she either covers for everybody or nobody (but maybe her friend) and they split the bill. she specifically singled out her bf when it was her mother who ordered the most expensive meal, and thats not right. alternatively, if she didnt/couldnt cover the whole bill, she shouldve requested her mom cover her meal and covered the rest of the bill for everyone else since the rest of the party got cheaper meals, so she probably couldve managed that? idk, regardless, OP is NTA for feeling hurt and a bit angry

Maybe she was going to pay for you but then her mom ordered something very big and decided not to because she wasn't going to pay for a friend either but I guess she owes her friend money so I think she was going to pay for you but then when her mom ordered an $80 item she probably couldn't afford it that's my thinking on this