I (18F) have a bf (19M) and a friend (19F) who acts too friendly towards him, I need advice on what I should do

I (18F) have a boyfriend (19M), and he is around my friends often. one of my friends (19F) acts very friendly towards him, calling him nicknames that go as far as her “little passenger princess.” she shares intimate details about guys she’s sees and her sex life to him, even though he has made it clear he isn’t interested in hearing those things. she always talks about him, and asks what he’s up to daily, how he’s doing in school, if we are going to hangout, and what we do when we hangout. she used to tell him and other people to leave me, because i don’t “treat him right”, and would tell me to make sure i’m not just with him bc it’s comfortable, and never told me any of the things she tells him. She has told past men she had talked to, to take after him in what he does for me in my relationship. she has told me many times she doesn’t want my man, but her telling me that on multiple occasions makes me question the legitimacy. I don’t know what to do in this is situation, and I don’t know if i’m crazy for thinking she is interested in him, because in the past she has snuck behind my back and had sex with people i was talking to without me knowing, and then hiding it until i found out. it is a trend for her to get with guys i have been with, and i don’t know if she is trying to do the same now. please any advice is appreciated because i have no clue if i should say or do anything about it.

edit: my boyfriend only engages when he has to, because she is my roomate, and he comes over to my place a couple times a week

TL;DR :
my friend (19F) acts very friendly to my bf (19M) and had continued to do so, after getting a guys i (18F) have gotten with in the past. What do I do, or say in this situation?