WhY r SuM gIrLz So IgNoRaNt (mostly for girls but guys can answer it too)?

Ok so apparently me and my friend are in some kind of argument because ic alled her out on her bullshyt. I told her that she is starting to act like a little ***** because she's always hanging on to MY boyfriend.I love my boyfriend ta death and i know he wouldnt do anything to hurt me but she's always around everytime i wanna be alone with him. LITERALLY! She's always on his arm and messin around in his hair and flirtin and all that stuff.So i called her out on it and she got all pissy headed about it and told everyone i wuz being a ***** so yeh there's muh question. Why are some girls so ignorant?