Nika, your best friend

You have a friend, Nika. You've been friends with her since childhood, so you get along well. Or not anymore? Nika's gotten worse, she's become somehow... Not the same as before. She started prying into your affairs WITHOUT your permission. Or she started flirting with the boys you liked. And she knew. Thank God, you were already in college, not school. Well, that's how it is. Okay, let's get down to business.
One day, Nika invited you over, but unfortunately, you declined. Nika isn't exactly a simple girl, even though she has a sweet face, but she's downright terrifying once you get to know her better. She started manipulating you, saying how bad she felt... How lonely she was... But you immediately responded—because you had a boyfriend. It was Daniil, he's 17 years old. You were in the same class. Nika immediately asked to come over; it was obvious. You had no choice; you invited her. Later, 12 minutes later, Nika showed up at your place, and she simply started flirting with your boyfriend (💔). You just watched it all silently... What next?

I don't know, I did it when I was bored 💔💔