My sister has been being a douche lately.

[Hansome duded]

have love with her boyfriend to get her jealous

she doesn't have one - every boy she asked rejected her, and every boy that asked her was rejected.

fail, you need the experience

[Ad Bot]

[The Resonte!]

give her a hug whenever she does it

[MrKitKat]

Stick it in her pooper

[Cool Boi]

Slap her back
With napalm

[Renekar]

why don't you lose some weight fatty!!!!
does she take any medications?

[Electrk.]

go on a diet

[Butler]

tell her to knock it off
ask your parents about it
avoid the slap
wear a scary mask all the time
tape a fake hand to your face for free high-fives
carry a spray bottle and spray her before she tries to slap you
say "HA! I blocked your hand with my face!" extremely loudly at her every time she does it
crawl everywhere across the ground for one day
get a really annoying app that plays a fart sound every time she slaps you
get a really annoying app that plays a crowd laugh track every time she slaps you
fall over on the floor and pretend to have died when she slaps you
fill your mouth with water and the next time she slaps you you'll spit it out all over her

or do all the above and see how far you get through the list before she stops

This actually made me laugh

[Bacon Pancakes]

Date rape pills. :^)

sig'd

[Bahamut]

smoke her out just smoke hella weed with her
once you're baked out of your minds console her and be all yo why do you do that bro

[HissingWalnuts]

Lock your door or put a large heavy object in front of it.

[Tonkka²]

When she sleeps, tie her to the bed and shovel sand in her vagina

that'll teach 'er

[Clone v.117]

Is she hot?

[Tetris]

how old is she and how old are you

this is very important

[pefu19]

inb4she'sonherperiod

[Yosher]

Kick her ass. I'm not just talking physically, but mentally as well. Find out about her worst fears. Make them appear in her daily life and make sure that she can't get away from them easily. Defeat her.