everything and nothing. there'll be tiny tiffs about things like: 'but it was my turn to do the washing up!', or 'you forgot to buy eggs!', or 'i'm driving, so i pick the music!'. silly things. not serious things. or maybe if arthur keeps buying more plants for the garden and there's no room. or toni buys another new pan and tries to hide it. there's a moment of 'uhh... did we really need more?' but it passes fast, because it doesn't actually matter. it's not a big deal. and if they've done something to make themselves happier, then who are they to get in the way of that?
the only times they might actually argue will be times where there's a lot of stress in their lives, and even small things will set them off. they're both good at letting things build up before blowing their lids, and it can get ugly. some time apart, or an open and honest conversation, will help. they recognise that they're similar - sometimes too similar...
oh, and of course, if they're watching football or something and are supporting opposite teams (god forbid it's an international friendly), if one of them celebrates a bit too hard then they're sleeping on the sofa that night :)
14. what nicknames they call each other
i reckon arthur has a whole arsenal of nicknames and petnames under his belt. changes on the daily. he can go from calling toni 'darling' or 'sweetheart' to later calling him literally anything whacky and wonderful, like 'pumpkin', 'buttercup', 'boss man', 'honey bunny', 'everything that is good and right in this world'... he likes the way toni will smile or laugh, especially the more elaborate or ridiculous they get. one of life's little joys.
with toni, i've always maintained that he'll call arthur 'turrón' - i think that's the one nickname he'd always use. sweet like nougat, with a bit of a bite. but on the whole i think he uses nicknames less than arthur does. he'll adopt the usual 'amor', 'querido', 'tesoro', of course, but arthur is a relentless force in that department, there's no way he can compete haha