So, this girl I've been talking to for a couple months and known for 3 years... We're both 18. She is always very submissive to me, always does anything I want her to do, I took her virginity, she always sucks my dick like crazy, multiple times if I want her to, always degrade her like a little whore in bed.

About 2 weeks ago when I was at her place she told me that she knows I'm talking to other chicks. I told her yes, but it's nothing serious and that they're just friends. Everything was good after that but she was pretty upset.

We were just talking on the phone and she goes "Oh, I completely forgot I had some plans", I ask her what plans and she says "Well I was supposed to meet some (male) friends (in my native language you can say male/female friends with their own words)". I kept it cool, asked her "Friends?" and she acted like she didn't know what I was talking about "Yeah, some old friends I was talking to a year ago blah blah blah we were supposed to go with my girlfriends blah blah blah and they all wanted to drink and I blah blah". I said "So we're having friends now huh?" and she still played dumb or it actually didn't spark her what I was talking about. She also knows I'm against drinking. I started talking in a more disinterested/aloof tone and we cut the call shortly.

She just messaged me "I love you, and i forever will, you are the person I need, you are the only bright star of my future" as I'm writing this post.

I contemplated telling her right then and there on the phone that I don't like whatever she said, but I didn't, did I do well?

How do I run good dread on her and make her know that shit isn't cool with me? Something like "I was hanging out with my (female) friend" when she asks what I was doing?

Also, I'm noticing covertly setting boundaries doesn't work well with her and she doesn't seem to grasp it until I tell her strictly what shit doesn't slide. Should I tell her "I do not tolerate any male friends, talking to other men and hearing about other men. If you keep doing this, I'm not sticking around. Understood?"