Gives nose/forehead kisses
Iwaizumi likes to give nose and forehead kisses when Oikawa least expects it because he likes the surprised blushy look on Oikawa’s face.
I’m not sure jealous is the right word since (if I remember) to feel jealous is to basically have a worry that someone will take something of yours away and they don’t really have that worry because they trust each other a lot. However, Oikawa can be rather possessive of Iwaizumi at times.
Picks the other up from the bar when they’re too drunk to drive
They both do this, but Iwaizumi tends to be the designated driver more because he usually doesn’t care for the taste of alcohol.
Takes care of on sick days
Again, they both totally do this. Oikawa tends to get sick more though, mostly because Iwaizumi has the “Immune system of a God” (Oikawa’s words. He’s very envious)
Drags the other person out into the water on beach day
Iwaizumi drags Oikawa. Oikawa doesn’t like to get his hair wet (and also hates having to adjust to water temperature even though he’s fine once he does) but Iwaizumi just picks him up and dumps him in the water so Oikawa doesn’t have anything to lose
Gives unprompted massages
Oikawa. Iwaizumi has a bad habit of getting really tense and worked up so Oikawa will just start giving him massages when they have down time
Iwaizumi prefers to drive because he finds it relaxing and he tends to get carsick. Oikawa is fine being shotgun as long as he gets DJ privileges
Brings the other lunch at work
Oikawa tends to bring Iwaizumi lunch because Iwaizumi’s boss is LGBT+ friendly (and Oikawa’s isn’t). Oikawa also likes flirting with Iwaizumi’s coworkers but mostly to get his Iwa-chan riled up.
Has the better parental relationship
Iwaizumi. Oikawa has a strained relationship with his parents. Great relationship with his sister and nephew, though!
Tries to start role-playing in bed
Neither. It’s not really their thing (Iwaizumi figures Oikawa is dramatic enough as is). Neither would be able to keep a straight face while doing it because they’ve known each other for so long and have a hard time imagining each other as anything else (school plays were a nightmare for these two when they were kids).
Embarrassing drunk dancer
Iwaizumi, another reason he doesn’t drink too often. He’s not half bad at dancing normally though
Still cries watching Titanic
Iwaizumi. Oikawa cries at the end of ET though so they have a mutual “no judging or speaking of” agreement.
Firmly believes in couples costumes
This has Oikawa written all over it. Iwaizumi complains heavily, but he usually gives in because his life is easier this way (and he likes seeing Oikawa’s smile when he does)
Breaks the expensive gift rule during Christmas
Iwaizumi. Gift giving is a love language of his and when he sees the perfect Christmas gift he can’t really stop himself, regardless of cost.
Makes the other eat breakfast
Oikawa makes Iwaizumi eat breakfast. Iwa tends to skip the meal because he has a hard time waking up but “Breakfast is the most important meal of the day Iwa-chan!~”
They’re both really good at this. Oikawa because he keeps important dates in his phone with notifications to remind him at least two weeks in advance and Iwaizumi because he just has a knack for remembering dates (Oikawa always hated him a little when they got their history exams back)
They both think of it pretty close to the same time, but Iwaizumi beats Oikawa to the punch when it comes to bringing up the subject. They had kind of talked about it a little when they were younger, though, and had mutually decided to talk about it again in a few years.
THANK YOU SO MUCH FOR ASKING!!! :D