AITAH For buying chestnut milk tea?

AITAH For buying chestnut milk tea?

Me (30F) and my girlfriend (29F) have been together for 5 years. She has been struggling with stomach issues since childhood and we recently discovered she’s allergic to a certain sugar in some foods. This means that there are a lot of things she can’t eat like pistachio, mango, gluten, apples, onion, garlic and the list goes on… Nothing serious happens if she eats any of those foods, a stomachache and bloating at worst.

We were driving around town and were talking about this new boba shop that opened nearby and how good their Thai tea and strawberry milk tea was. We decided to get one drink to share tonight. When we arrived there I wanted my gf to go in and order with me because I know she knows her allergens best. I try my best to remember all the food she’s allergic to so I won’t cook food that she can’t eat. My gf wanted to wait for me in the car because she has social anxiety (I do too but I try to accommodate her more). I said fine and asked her if she is okay with whatever I order. She said yes and even a milk tea is fine. I saw that they had chestnut milk tea on their menu and thought that seemed pretty interesting and ordered it. I told my gf what I ordered and she asked why I ordered such a random ass drink? She googled chestnuts and in large amounts they do contain that sugar she is allergic to. She was upset at me for not asking her beforehand. I immediately apologized and said I should have asked her but I wasn’t thinking because I was feeling socially anxious. I offered to buy her her own drink of choice but she refused and argued with me the whole drive home. I kept apologizing and took responsibility for what happened and asked that for future moments where she wants me to order food for her I would like her to remind me of her allergy. That pissed her off more and said I was trying to blame this situation on her. I dropped her off at home and I decided to continue driving around town take some space and cool down.

So Reddit, AITAH?