I'm going to call someone a degenerate
Why do you think she is a degenerate?
She cheated with her best friend's boyfriend for over a year.
You don't have to agree with what people do but you don't have the right to insult them. People will just think that you are mean.
It's like she's been two timing him. You don't think that cheating is something wrong?
Even if she cheated it is not good to call her names. It will make you seem like a bully to others and they won't want to hang around you.