I did this in high school during my freshman year. When she told me we were just friends, I confided in her that I liked her, or at the very least made it obvious. She proceeded to tell me she was too busy looking for a girlfriend for "her friend", and when I asked her why she couldn't find me one, she said "Well I don't know anyone that would be interested in you?", like it was some sort of insane question I asked, which in turn needed to be questioned itself. Then she introduced me to her friend the next week, and it turns out she was now dating him. I never spoke to her nicely after that. Whenever she pretended to be my friend in the hallway I would call her a whore and a cunt.