So some background for what led up to this situation. My cousin is having her male friend from out of town sleepover at her place for a few days. She is also in a 1.5 year committed relationship with her boyfriend who lives apart from her. (Who recently became a friend of mine) Last night when her SO was not over she decided to bring said friend into her bed to watch movies. He fell asleep and then she fell asleep soon after. My sister tells me this saying they were cuddling also. I give her my opinion on the matter. Saying "I would not be happy at all with my SO if he brought a gal friend into a bed to cuddle and fell asleep. In *my relationship* I'd consider it microcheating as its a form of intimacy. Intimacy I wouldn't be comfortable with my SO sharing with anyone but me. I be mad if I was her SO but my boundaries may differ and in the end it's up to him." As that's the case for me I wanted to know if I was overreacting and went without outting her to people asking "if you found out your SO purposefully or accidentally was found cuddling in bed with a friend of the opposite gender or preferred gender how would you feel." I wanted outside perspectives to have a more informed opinion or see if it was a bigger deal than I thought. Most shared the same opinion as me. They didn't like the idea but up to SO.  I go to bed after a long day and wake up to her chewing my head off saying how dare I accuse her of cheating. That it was an accident and it's my sister's fault for not waking her up or it be a different story than it was. That as her cousin she's mad I would shit talk her. I told her I didn't shit talk just stated an opinion. That I asked others without saying her name or letting anyone know who it was about so if the overwhelming majority said it was wrong I could privately pull her aside and see her side of the story but never got the chance... Am I the Asshole for saying the situation was disrespectful and trying to get opinions in which I didn't out her?