AITA for refusing to pay after my girlfriend brought her ex on our cabin trip?

My girlfriend looked me in the eye at the cabin check-in desk and said, “My ex is staying with us this weekend. If you make this awkward, you can drive yourself home single.” I smiled, removed my card from the reservation, and said, “Enjoy the weekend you planned without me.” ---------------🐋Whale Tales🐋--------------- #reddit #stories #redditstories