My GF '20F' is upset at me '21m' for getting a drink with my parents. I don't think it is an issue?
Some background: Me and my gf have been together for around a year and we moved in together about a month ago. We've had our share of problems but overall I'd say we have a good and solid relationship. When I turned 21 when me and my friend were talking about getting a drink together she said that if I ever go to a bar without her she would be incredibly upset with me because i am doing an activity that I know she can't go to due to being underage. She has stated time and time again that it's not because I'm going to get a drink but explicitly because I am going somewhere I know she can't go.
That brings me to last night. My parents call me to talk about paying for my college tuition. Nothing. Crazy they're just making payments. At the end of the call my mom said at the end of the night they were going to be at a bar that's a 5 minute walk from our apartment and asked if I wanted to have a drink with them. I said yes because I've never gone to have a drink with my parents since turning 21. I have a good relationship with my parents but I never go see them so I figured why not they just paid my tuition and I'll have a drink with them. That's when my gf got incredibly upset at me because I was going to a bar with my parents knowing she can't go. She brought up my selfishness and how it's pathetic I'm going there to appease them after paying my tuition. We fought and it ended with deciding to sleep on the couch for the night and we still have not spoken. I desperately need a sanity check because she is steadfast in her position that I was wrong for going but I genuinely can't see the issue. Did I mess up?