Should i continue this friendship or leave?

Is my best friend breaking the girl code? So a little back story my best friend and i have been friends for the past 2years,and i live in a joint family,so as she is my best friend i introduced her to all of my cousins then one day she told me that my cousin( lets call him X) and her have a thing but X is not into stable relationships and prefer more casual relationship that’s why they both stoped talking,now she started talking to my younger cousin and one day we were having a sleep over and we had some drinks its was my first time so i got drunk pretty quickly but then i remember my younger brother and my best friend started making out thinking that i am drunk and will not remember anything,look i am not again her dating my brother but my father calls her beti and then she had make out with both of my cousins and she is kind of a attention seeker and talks to alot of boys m..should i stay friends with her or not?