AITA for ending my engagement after my fiancée chose her ex over me that night?

My fiancée slid my spare key across the coffee table and said, “My ex is staying here tonight. If that makes you feel small, leave before you make me look bad.” I picked up the key, slipped it into my pocket, and said, “Done.” 3 months later, she showed up at my door with a suitcase and asked if I still thought our relationship was unfinished. ---------------🐋Whale Tales🐋--------------- #reddit #stories #redditstories