AITA for refusing to pay for my girlfriend’s meal after she “tested” me on a date?

So me (27M) and my girlfriend (25F) have been together for about 8 months. Things have honestly been pretty good overall, but something happened this weekend that completely threw me off. We went out to dinner with two of her friends. Before we even got there, she jokingly said something like, “Don’t embarrass me by acting cheap tonight,” and laughed. I thought she was kidding, so I ignored it. Dinner comes, and everybody starts ordering expensive stuff. I’m talking appetizers, cocktails, desserts, the whole thing. I kept it reasonable because I’m trying to save money right now. At the end, the bill comes out to around $340. The waiter asks how we want to split it, and my girlfriend immediately says, “He’s got it,” without even looking at me first. I laughed because I thought SHE was joking this time. She wasn’t. I quietly told her beforehand I only planned on paying for our own meals, not her friends too. She got annoyed and said a “real man” would just handle it without making it awkward. At that point I got irritated and told the waiter to split the bill separately. Her friends went quiet, my girlfriend looked embarrassed, and the whole mood died instantly. Later that night she told me I failed a “relationship test” and said she wanted to see if I was generous and capable of “providing under pressure.” I told her I’m not interested in being tested like a lab rat and that if covering three extra people was important, she should’ve communicated that beforehand instead of trying to corner me publicly. Now she’s barely talking to me, and apparently her friends think I’m broke and childish over the whole thing. AITA?