Why does a girl tell me she likes me only as a friend, but she still gets mad if I start going after other girls?

It’s not complicated.

It’s simple. Look how simple it is…

She tells you she only sees you as a friend
You STILL have hope in getting into her pants
So you let her talk shit to you, behave shit to you while I’m a guy who will say..

“Listen woman. I gave you the amazing opportunity to know me and date me, and be my lover. You said no. So whatever I do now, smile at girls, kiss, fuck, eat them out, whatever shouldn’t bother you. Unless it’s because you desire to date me and be my lover. So which one is it?”

Girl - just friend

Me - Good. Then behave like one or stay the fuck away.
I can say that because I don’t fear losing her. You do because you still have hope that she might change her mind.

Forget it.

Talk straight to her. Set boundaries and let her know, she pisses you off again, you ain’t no nice guy who will let her do that..

Say it in your own way, no problem.

I’m more of a direct guy and can’t be assed with any complications.

Stop letting girls walk all over you and psychologically seduce you to be passive-aggressive.