AITA for refusing to keep paying for my girlfriend after her friends mocked me?

At my girlfriend’s celebration dinner, her friend raised her cocktail and toasted, “To Alex, the quietest guy at the table and somehow still the most useful.” My girlfriend laughed and slid the bill toward me. I smiled, asked the server for a separate check, paid for my own meal, and left them staring at the $900 bill they thought I would be too embarrassed to refuse to pay. ---------------🐼Panda Tales🐼--------------- #reddit #stories #redditstories