Hostility is so much easier to deal with than friendliness, for some reason. Me and non-familial hostility are old pals, dating back to the first time a drill instructor got close enough to kiss me and instead questioned my mother's past morality at the top of his lungs (it wasn't the shouting I minded as much as the bits of spit I couldn't wipe off my face. See the end of the courthouse scene in Blade Dancer for more emotional details.)
Hostility is always a stand-up guy, though. Pure, honest, right there whenever you need a kick in the pants. He makes you feel like a little girl in a stupid dress and too-tight white Mary Janes, made to dance the polka at a family wedding. Hostility is the older, flatulent boy cousin who hates you more than dog puke and will give you at least one Indian burn and a wedgie before the accordion player takes a break.
It's a dance you endure, because you know where to find dead bugs in the wedding hall, and at some point during the evening, Hostility will leave his soda and food unattended.
Friendliness is also at the wedding, but he's not a family member, or flatulent, or scowling at anything young and female. Someone you know makes vague introductions, and he smiles at you. You don't smile back because he might assume something horrible, such as you like boys.
You watch Friendliness, and note that he has good manners, doesn't fart recreationally and is polite to the grownups. He dances with girls, but none of them leave the floor rubbing their arms or pulling at the back of their dresses. You might think he's a suck-up until you see him quietly stop Hostility from pinching your little sister until she cries.
You realize that Friendliness does not know where the dead bugs are, or maybe he does and doesn't care. This causes you to admire Friendliness from a safe distance, and part of you wishes you could be like that -- if that's what he's really like. You don't know. Not like Friendliness is easy to read. Friendliness is too much like grownups, and you're still a little kid.
Then Friendliness does the Worst Thing Possible: he comes over and asks you to dance. Politely, without your mother or your older sister asking him to. He smiles again. He's got a nice smile. Why is he wasting it on you? Doesn't he see your stupid dress? Your too-tight shoes? Not like you can dance anyway.
Do you take a turn on the floor with Friendliness? Your answer depends on how many times you've been forced to dance with Hostility, and whether or not you made use of those dead bugs.