<human>: Can you give me the gist of the text in a nutshell?

(All names changed) 

A little bit of background: I have been living with a girl named Mia for almost a year. We have had a rough 2 year friendship and I am moving out soon with the intention of cutting off contact with her.

Recently, Mia has developed a crush on Jeff (she admitted this to me). Jeff actually has a girlfriend and Mia is well aware of this. However, she invited him over tonight for wine and a movie and ended up cuddling with him on the couch. This makes me very angry. Should I tell the girlfriend what is going on? I am almost positive that Mia is not pursuing a friendship and is trying to seduce Jeff.

She is absolute scum. She needs to realize her actions have consequences.
<bot>: My roommate is trying to be a home-wrecker. Should I tell the girlfriend? How should I tell her? (I am not friends with either her or Jeff).