I'm going to be called a cheater even though we weren't exclusive.
What made you think that you guys were not exclusive yet?
She said that she has better looking friends than me.
I think that it is time for a discussion about it. You need to define the relationship in order to know what boundaries are set.
I would but it's a whole lot of drama and I'm trying to keep it low-key.
If you want to keep it low-key, then you need to communicate that with your partner. There already seems to have been some confusion between you two about if you are exclusive or not. If you don't talk with her, these issues will just get worse.