Avoid dating girls who act like 15 year olds...

Nope, it's never happened.  The only time she ever "sajiaos" is in jest, and in private....because she knows I hate it.

She tried, cried went to the bed room. I didn't follow, she stayed like 10h in the bed room, i had a nice day. next day all was forgotten.

just don't give in. after some time they will give up

Sometimes when I see it happen to local guys it makes me think that both parties are just applying the formula.. she sulks, pouts and acts like a 4 year old that can't get her way, then he has to be all apologetic and make amends because he hurt her feelings so now he is in the wrong and has to cave in to her demands plus do something extra as compensation for being so cruel as to wrong her in the first place, because she a beautiful delicate princess who is easily hurt by callous and selfish people.

So he spends more than he can really afford on the handbag she wanted plus a pair of shoes to go with it, she becomes the delicate princess again, he gets to keep his girlfriend and they are even again.

It's bargaining tactics.

My wife doesn't do it.

My wife doesn't do it either.  If she did she wouldn't be my wife.

My ex-girlfriend from Hunan used to 'sajiao' me all the time. We fought often. I couldn't handle a woman that occasionally felt like acting like a 9 year old girl. I learned after some time to give her the exact opposite of what she wanted: Which always pissed her off something serious. Some Hunan girls are F#$KING crazy!! The sex was out of the world though... I guess it's a package deal. 

what is sajiao ? some kind of buttsecks ?

I've never actually seen this. I've seen moody, quiet, sulky. The aggrevation I get is not listening or answering questions, never ever answering questions. That's where my ''No why?" comes from, "Why?" is such a common answer. Couldn't the answer be ''yes'' or ''no'' just once?