Can't I just tell my best friend that her and her friend are obnoxious together
What do you plan to say to her?
I will say, She is annoying as hell and so are you!
Many rude people are deeply insecure, with low self-confidence and a lack of understanding about human behavior. Try to keep your low opinions of others to yourself and live peacefully.
Me not the asshole. She annoys me the most.
It's better to just distance yourself from them when they're together and annoying you. You may lose your friend if you're rude to her.