QUESTION: Should I have kissed her? OR any criticism

BTW im drunk right now
I talked to this girl (7.5, but relative to the party a 10) I used standard game for at least an hour, over time, and I was totally in. I have my arm around her and its going good when all of the sudden she sees a guy and says whats up.

Turns out the guy is her BOYFRIENDS younger brother. She was completely testing me by mentioning this, otherwise she would have kept it a secret. I diffuse it by putting the focus of the convo on the borother asking how old her bf's brother was.

She ends up telling me that her bf is 5y her senior. "Well thats good for a girl, you gotta go where the experience is... did it pay off" After a little bit of a too long delay she said that it had paid off. (I knew that she wasnt happy with her bf and framed it to seem like- he BETTER be a good lover; which he wasnt according to my perception of her reaction. Plus she leaned into my arm!)