Lux and Garen. Unless you really want to do Lux and Fiona, for potential humor value.
I’ll do Lux and Fiora because a) yes, it’d probably be pretty funny, but also because b) Lux and Garen are siblings and that’s not really my cup of tea. Sorry!
Send me a ship and I'll tell you who:
cries when someone dies in a movie?Lux does, but she’s very adamant about reminding Fiora that she doesn’t cry after every death.
wears the ugly holiday garb?Lux, again. Fiora isn’t exempt from ugly sweater-wearing, though.
pays for the meals?It’s probably a pretty even split between the two. Fiora does it because she doesn’t want to look bad, and Lux does it because— well, that’s just what she does.
slams the oven door/plays the trombone?Fiora plays the trombone because a) it’d be insulting to let Lux take the lead and b) she, for some reason, knows how to play the trombone. Lux just goes along with it.
brings home stray animals?Lux probably does, but there are very few - if any - strays left on Demacia’s streets. If there are, they probably don’t stay on the streets for long.
leaves the bathroom door open?Fiora.
tells the ‘dad’ jokes?Lux is very guilty of this, but she doesn’t make a habit out of it; Fiora doesn’t understand a lot of them and it’s too hard to explain them to her.
wants kids more?Lux, agaaain. They’re both too busy to be looking after kids, though, so it’s probably a thought best kept ‘til later.
travels more?Lux. Her work in the military demands it.
spends more cash?Fiora. She does it to spite her father.
buys the things in infomercials?Lux. For absolutely no reason at all.
draws in the dust on their car(s)?Lux.
starts the snowball fights?Fiora, actually. Lux doesn’t like it because, ironically enough, she tends not to play fair.
throws away directions to things?Neither of them do. Throwing away maps is Ezreal’s thing.
puts up holiday decor?They both do, but only because Lux makes Fiora do it with her.
more likely to forget to bathe?Believe it or not, it’s probably Lux. Missions tend not to have portable bath tubs.
gets more obsessed about things?It’s a tie. They obsess over different things, but they obsess over them all the same.
sings in the shower more often?Lux gets caught singing in the shower, but Fiora probably sings in secret.