Friend betrayal am I wrong for this whole situation?

Tasha

I been friends with this girl name Tiana we met each other at a restaurant work place so I reconnected with a boy I knew in high his name is geno who had a crush on me and wanted to take me out to the movie's so my friend was going through issues with her boyfriend I felt bad for her so I ask my high school friend is it ok can my friend come to the movie's with us he said sure then me and my friend met him an all of sudden I see my friend flirting with him I lost my attention and said what is she doing it's not like me and my high school buddy was dating I felt like he disrespected me and tiana disrespected me so found out the next day by tiana they met up behind my back they hang out and had casual sex I was mad cause I felt like tiana betray me she was supposed to be my bestie and I stop talking to her and my old high school friend geno 4 years later I spoke to my former friend tiana again and she still doing her betrayal again bu trying to talk with other guys I'm friends and flirting with I cut her off again!!