Why does my bird bite my neck?

[AlexaInchima]

I have had my baby 9 month old conure for about a month now. She is getting very used to me, and my lovebird. She eats and drinks, and is completely normal! Its just that, sometimes she wants to come up and sit on my shoulder. I try not to let them sit there too much cause it means dominance, but she sways back and forth, bobs her head, and sticks out her claw to try to reach my shoulder. I cant help but let her! When i let her, she happily climbs up and talks in my ear. I give her treats for being good! BUT! There is one thing i hate when she does! She pinches the back of my neck! It hurts so much! and she wont stop! I tell her no! but after two seconds, she does it again! And it was the same thing my lovebird did, but she stopped i guess. Anyways, so im not sure why she bites me, but before she pinches, she huddles close to the side of my face and gives me kisses, then she will cuddle beside my neck, and then will just rub her head against my neck. Right after that she will pinch! Does she think im a bird and is trying to preen me? I feel bad for taking her off because im not sure if she is trying to hurt me or is trying to show affection! Please help! I dont know what to do!!