yeah breh, like Darealness said, this one is kind of on you. should have made it clear from the get go. OR should have asked for seperate bills. Not feeling her style though. she's pulled some lame shyt. chicks like that are not quality. I even know legit golddiggers with more style and class. The way i see it, a chick with real game won't even need to pull these silly bathroom moves. She'll genuinely make you feel like paying for her as if she was your girlfriend. She will make you feel like wanting to take care of her without her even trying.
i used to be VERY anti-dates. I still am to some degree but i've relaxed my ideas on this because i realized it's not dating itself that's the problem. it's the intent behind the date that's the problem. it's the chicks we choose to go on dates with that's the problem. I keep saying it but it's really something i believe in. Pick chicks that are choosing you and you will not even have these types of problems.
I told this story before but one of the last chicks i went on a date with, she's the one who asked me out, I was gonna pay for my ticket but she legit tricked me into paying for mine. she was choosing hard. last chick i went on a "date" with, she asked me if i wanted to see a movie, we went dutch on the tickets. was hungry so i ask her if she wanted to go grab something to eat. Paid for her shyt cause it just felt right but i still made her put in work and told her to put that shyt in her bag to sneak it in the movies (i was inspired, lol). You gotta go with your gut and what feels right. I made a post about awkwardness once. It's really fascinating how scared we all are of awkwardness. Awkwardness is not the enemy. Your fear of it is. Awkwardness can actually be your ally. Once someone feels like you're trying to avoid awkwardness, they know instinctively they can control you. We'll do almost anything to avoid it. see that chick in the first example, she was feeling me at that point in time and she paid the tickets while i wasn't there to avoid an awkward moment. She wasn't willing to risk letting money or awkwardness be an obstacle in us getting closer. She didn't want to even risk making me feel like she's trying to play me because she feared i would dismiss her for it. And it has little to do with money or looks. Once you learn to give up control on who chooses you, you're in business.
Sorry for going on a tagent, as far as your situation i would have played it like this. I would have waited for her to come back from the bathroom, grin at her very slightly like

and pay for the whole thing without saying a word. Cause really it's not even about the money. I would have REALLY made her feel awkward and lame without saying a word. The beauty of it is, if you don't say a word, she has no "in" to defend herself. it's like you're telling her "you stupid petty bytch, I would have paid either way but you pulled a basic move to play me for something i was already gonna give you. now at least i know to avoid your calls, thank you

". And she can't answer cause it wasn't said in words. funny part is looking at the little hamster in her head racing to find an idea on how to gain back her dignity. Then I would have told her it's getting late and blablabla and drop her at her place. If she gives signs of offering puss, i would not even entertain it (and frankly it's not even playing cause the bathroom shyt would really be a turnoff). After that, never call or text, short and vague replies if she texts until she either makes me want her again or gets tired of this stupid game. After that 9 chicks out of 10 will go crazy and do anything to get back in your good graces cause that shyt is ethering their soul and self-esteem. Then you eat! That's the player way to handle it.
the mature way is practically the same. You just pay, drop her home and straight bushes. If she sends you texts or calls and asks you why you didn't call, just say you're not feeling it and KIM.