I think it’s pretty obvious that you’re dealing with a young, immature party girl: the opposite of marriage material. Her priority in life right now is to party and act stupid, not you, not marriage and not your relationship. She isn’t taking you seriously or putting you first and she isn’t ready for a real, committed relationship. While she’s out drinking, grinding on random dudes’ bajoings, and fist pumping, you’re sitting around in your room thinking about your wedding cake. Do you see how ridiculous that is? You sound young and naive and soon you will realize, either now or the hard way later, that marriage is the very least you should be thinking about, and that this girl is not even worth your time. There are so many nice, sweet, attentive, relationship-ready women out here looking for committed men to love them, and you guys stay breathing up the necks of obnoxious party chicks.
Answer: Stop it.