Hey anon! Sorry I took a while to answer, phandomestic and I were working on these last night! You led us to a conversation that gave us tons of pheels, so thanks.
(Most of these headphanons are written with the idea in mind that Dan and Phil are a couple, just so you’re aware - I mean I assume that’s what you wanted, but if not I’m sorry)
Dan sometimes stands outside Phil’s room to watch him film (and Phil has to redo a lot of takes because of Dan’s laughing) because he still love’s Phil’s videos just as much as when he was a little fanboy in his bedroom, miles and miles away from him, and now he gets to see the videos being made and he get to live with the man he’d idolized and moved across the country for and it’s basically a modern day fairytale and sometimes he just can’t believe that this is his life.
Dan is way clingier and cuddlier than Phil. He’s just a big fucking sap even if he doesn’t like to admit it. That’s why he’ll always lovingly tease Phil - he wants to flirt like all the time but doesn’t want to admit that he wants to flirt.
Dan loves and adores Phil and basically looks at him like he hung the stars (that’s not even a headcanon that’s just TRUE) no matter what Phil’s doing. Like he could just be setting up the camera or prepping for a gaming vide or in their lounge in pajamas with a scruffy face watching anime, and Dan can’t help but see Phil as utterly beautiful. A part of him regresses into 2009 Dan and he’ll randomly say “I love you” just because he CAN now because Phil is WITH him.
They want to get married in Manchester because it holds so many special memories. Maybe in December.
When Phil visits his parents he likes to go to Manchester and visit the Starbucks he and Dan used to frequent, sit on their couch and drink a caramel macchiato and think about how much their lives have changed since they were just two young guys making silly videos and falling in love.
Phil loves to listen to Dan rant about formula one and kanye west and spoilers and whatever else he’s passionate about, not necessarily because he’s interested in the topic (he couldn’t care less about the artistic merit of kanye’s work) but because he loves the way Dan’s eyes light up and how his hands move around dramatically and how he gets this flush in his cheeks, because he’s talking about something he’s PASSIONATE about and Dan is never more beautiful than when he’s letting himself be fully and completely invested in something.
As much as they like to ramble to each other about whatever’s caught their interest, their favorite moments are when the apartment is quiet and peaceful, and they’re sat next to each other on their laptops or watching TV, because they don’t feel the need to fill the silence. They’re happy and content just being near each other, lost in their own thoughts but always right next to the one person in the world they can’t imagine their lives without.
After someone brushes off Phil when meeting them, Phil pretends not to care but Dan gets absolutely furious, ranting about how amazing Phil is and “it’s in your fucking channel NAME damn it” and that night Dan takes special care to completely worship Phil’s body, which Phil usually does for him but Dan NEEDS to make sure Phil knows how loved he is and that Dan is never going to stop adoring him. The opinions of some
They’ll be out with friends and end up basically having an entire conversation with just significant expressions because they know each other inside and out, and it will take a few minutes for them to notice their friends have gone silent and are giving them amused looks, and “Honestly guys, I know you don’t need to talk to communicate but there are other people with you.”
They’re introverts, we all know this, but even introverts sometimes find people that don’t tire them out. That’s how they are to each other, and that’s why they retreat to a corner and huddle together when they’ve been at parties for a while and are feeling exhausted with all the socializing, and that’s also how they get though their longest days, because they’re always right next to each other and they’ll give each other a little nudge when the other looks overwhelmed, just to say “hey, I’m here, I love you, we’ll be home soon”.
When Phil gets angry about something, he holds it in but acts colder towards Dan, and it drives Dan crazy, because if Phil doesn’t TELL HIM he’s angry, Dan won’t know he needs to fix it. When Dan’s angry, he’s loud voices and caustic remarks, but even though he knows absolutely everything that makes Phil Phil, knows all of his insecurities, he doesn’t use those against him. He would with other people, people who aren’t such a core part of his life, but never with Phil.
When they have small arguments Phil gives in first for the sake of keeping the peace, but when they have big arguments Dan usually blames himself and apologizes first whether or not he instigated it.
Dan rolls his eyes and complains about Phil’s enthusiasm for all things Christmas, but he smiles behind his hand and secretly loves seeing Phil lit up brighter than any Christmas tree, running around and decorating their apartment weeks before he should, humming Christmas songs under his breath. And part of Phil’s love for the Christmas season is because it always reminds him of their first Christmas together in 2009, when Phil knew he was well and truly in love with this stupidly perfect teenager. When some part of him already realized he was going to spend the rest of his life with Dan.
Dan was always the little spoon when he and Phil got together, and even now that he’s bigger than Phil, he still wants to be the little spoon. He loves being held and Phil loves holding him, so it works.
Sometimes Phil gets embarrassed when Dan goes on and on about “Phil created” this and “Phil actually invented” that, because he’s a humble person, but he also loves having someone who’s ALWAYS willing to stick up for him, and who will ALWAYS recognize his achievements.
Phil has a bunch of “heart eyes howell” gifs saved on his computer and he’ll sometimes tease Dan about them, but honestly he thinks it’s really cute and flattering.
Sometimes when he and Phil are lying in bed, lazing around for a couple hours before they actually go to sleep, Dan will read phanfics while Phil watches TV. And every now and then Dan will nudge him and tell him to pause the show so he can read a funny bit, or he’ll to, “You’d never say that!” or “I wasn’t that obsessed with you.” (and Phil will give him a look and he’s grudgingly admit that he was, and still sort of is.)
When one of them is hurt or feeling really poorly, the other will get this sick feeling in their stomach until they know the other is actually okay, because even if they try to act casual and laugh it off, the idea of the other in genuine pain hurts. And Phil still remembers the night he had to take Dan to the hospital and how he’d never been so scared in his life, and he never ants something like that to happen again.
They always manage to distract each other. Like they’ll be trying to get serious business done in the same room, only to realize hours later that they’ve wasted their time with a debate about whether or not free will would exist if people could travel to the future (because that would mean their decisions were set in stone, and whatever they were going to do was already decided, right??)
When Phil’s away Dan tries his best to deny missing him, because they’re not that codependent, he swears, but then he’ll be cooking dinner and realize he’s automatically made a serving for two, and that the kitchen is far too quiet without Phil clumsily puttering around, and the loneliness will hit him again.
Phil loves to take photos of Dan when he’s not looking, enthralled with something else, because Dan when he’s relaxed and content and not putting on a face for anyone is just breathtaking.
On one of their early dates, Phil convinced Dan to watch a horror movie (hoping for some cuddles), but he found out Dan mostly just jumped and screamed bloody murder and certainly didn’t cuddle when he was scared.
Dan fucking LOVES Phil in formal wear - loves it so much, he ends up distracted basically every time they have a hosting gig. Hence why he ends up staring at Phil even when they’re interviewing huge stars.
Sometimes Dan will ask some existential question that Phil knows will lead to a discussion that will upset Dan, so he just changes the subject.
On some mornings, when Dan is tired and grumpy, Phil will follow him around the apartment and narrate what he’s doing like he’s David Attenborough in a wildlife special, dodging the pillows Dan throws at him and trying his best not to laugh.
Sometimes they’ll get annoyed because one will use the other’s phone or laptop without asking and then not put it back in the same place, and so they won’t be able to find it for a while, and the whole time they’re searching, the one that actually owns it will be insisting that they’re going to change the passwords and never let the other borrow it again (but never follow through).
I don’t have any more to add at the moment, except this - I’ve said this in another post of mine about Phan head canons, I’ll say it again, I’ll never stop saying it - no matter where they are or what they do with their lives, they’ll always be happy as long as they’re together, because they are each other’s home.