Y'know what? I'm late to the brotp party and I don't care! Show me some Sif/BRB love.
who steals french fries off the other’s plate?
Sif is the food thief, instigator that she is. She fully expects that he will get her back one way or another.
who jokingly moves in for the kiss when someone asks if they’re a couple?
Neither. Though Sif will reach for his hand, or step in close. Regardless, there’s no joke in it. Even when they’re not a couple they care deeply for each other.
who has to bust or bail the other out of jail?
Bill. Sif has a tendency to get a little out of hand in some situations. Especially situations where alcohol and celebrating are involved.
who gives the other advice/comfort about dating issues?
Both of them. Ultimately they both want the other to be happy, and neither one has had any particular luck in love. There’s probably less advice and more comfort which probably amounts to sparring, drinking, and maybe bailing Sif out of jail...
who shamelessly cheats at games by reaching over to cover the other’s eyes
Neither Bill nor Sif is prone to cheating, but should one of them start to gloat about their lead (and yes, that is definitely a thing that happens) then either one might take measures to level the playing field even if they have to ‘stretch the rules’ to do so.
who immediately calls dibs on the top bunk
Sif, because watching Bill try to squeeze himself into the bottom bunk always amuses her. She does, however, relent (usually) and let him have the top where he’s a little less constricted once she’s teased him a bit.
who starts and who wins the pillow fights
Sif starts it. She always enjoys a good fight in any medium. That doesn’t guarantee that she will win, but she definitely will not call a truce. A victor must be decided.
who says “your pants would look better on their floor” to the other’s potential crush
Sif. She can be very straightforward about these matters, and watching Bill fumble around for the right words brings her no joy. She wants him to be happy. First and foremost. Always.