what to do?

christina slapped me hard-on-the-face yesterday. she meant it as a joke, but i think she did it harder than she planned...it was completely unprovoked...she did it in the spirit of a pantsing (swoop in, swoop out). i'm pretty protective of my head...i was so shocked that i didn't really know how to react. i mean, we were just walking and talking about random stuff.

the dynamic between us is getting weirder and weirder. this happens to me a lot, where people become super comfortable around me and start to cross little lines. i think i come off as a kid so then people feel free to treat me like one, which usually involves using me as a whipping boy for their jokes. eventually they respect me more as a person or get to know more dimensions of me or something, but it stops.

this is the first time anyone's slapped me like that though. the thing is...she's smaller than me and older than me (by a lot), so i feel like i'm the lumbering giant swatting at a fly...what she's doing is annoying, but if i retaliate, i might really hurt her, so how do i get the message across? i've told her to stop multiple times. is this what it's like to have a younger sib? maybe i should just put her in a duffle bag and toss her down the stairs.

the weirder thing? she told me i'm her ultimate idol, which i can believe because if i tell her something on the field, she takes it super seriously, so it's not like she doesn't respect me. relationships are complicated.