@Ilyaaaaa
Like, hear me out.
Yes, two-timing is pretty b i t c h y and you should end your relationship with her. However, with the context you gave us, you were the one acting like a b i t ch cause you want your bestfriend to stop texting him because if you can't have him, you bestfriend can't.
Like???
"You can't change the world with pretty words alone."