Humhumhm...adult reimob is more difficult for me, more of a mix of choppy visuals than anything concrete,  but I'll see what I can do. I'm not including possible kids for now!

I like to imagine Reigen got a ring so early Mob was 16 (hiding it so well it wouldn't tumble out if Mob's powers went off during sex) so when he finally proposes it doesn't fit Mob's finger.

Mob already basically lived at Reigen's tiny apartment before they chose to move together. Reigen's relieved Mob's old club friends carry a lot of the bigger furniure. Less happy all of Mob's other friends talk about him like a geriatic old man. Ritsu comes over every day for the first two weeks to make sure his brother's not negatively affected by living with Reigen.

Marriage probably comes pretty soon after～ There's no reason NOT to marry early, they know they'll only want to be with oneanother. Mob brings up the idea first and is the one that eventually asks if they should just do it. They have a small ceremony after but I can't decide if western or traditional. Mob is so cute in shiromuku...I love to see it...
A lot of RMR like Reigen taking on Mob's surname, but I like the idea that they'll go with Reigen. Imagine not calling Reigen Reigen. I couldn't do it.

Years of married life together and the first time Mob notices a gray hair is when Reigen's kissing up his side, and hearing that startles Reigen so much he actually gets out of bed to see where it is. Has another quick crisis about becoming older and fearing Mob won't want him anymore if he starts actually going gray.
(Mob thinks it's so hot he's a little dizzy. He's got more stamina than shishou now and he WILL ride that old man until they're so exhausted there's no energy to worry about unnecessary things)

Hmmh I'm bad with headcanons I always start to talk too long...well, appearance-wise, I like what ONE showed us. Slim and unevenly cut hair.

I like the idea that he stays shorter than everyone else. He's still short and soft-looking but has muscle underneath, not to the extent of his old club but so that he feels proud of himself. He sometimes manages to drag Reigen out of bed for morning jogs around the neigborhood. Not a high success rate.

He's also more popular! He's been since his teens, and Reigen says the world is just realizing how handsome he is, as much as that flusters Mob. He turns down the occasional confession and then excitedly tells Reigen about them. Reigen's just happy for him.

Despite having his own apartment he still kept coming over to Reigen's tiny place instead. They get engaged, not suspiciously soon, around Mob's 23rd. Reigen was burning the ring in his pocket since Mob was 16, so it didn't fit when he proposed, and Mob cheated a little with his powers because he couldn't wait to have it on.

He's struggling with work – Getting used to the hell of actual worklife is much tougher than it was at the S&S office, and Reigen does his best to not let him burn out too young (be it a massage and a cozy night or marathon fucking). Reigen tries to close the office around the same time Mob gets off work so they can go for ramen like old times.

They'd want to work together at S&S again, but that's hard to do so that they could afford renting in their apartment. They could do it once they've saved up enough to buy their own place.

I've only ever had nine bookmark comments, but hmhm..hm...there's a lot that have amused me, but I have a really bad memory. Maybe the few where people said they'd use my fics to masturbate? It's great praise if I wrote something so good that it gets people off, but it was so surprising I was amused!

The one thing that stuck with me the best was a Guest named Cum who asked for my Twitter and they evolved into CAME in their reply, haha. Back then I hadn't shared it, so I do hope they saw my Twitter link eventually.

I'd love to go find the best ones, but I've kept nearly every comment I get from gratitude, so there's almost 170 in my inbox.

Ooh let's see! My old answers to a similar question still apply, and I haven't read fics in a long time, but if I were to list some more, hmhmhm...

Take Me Home is one I really like. REALLY like. Reigen sleeps most of it. It has Ojisan×Mob oral!! And delicious mutual reimob with a very desperate, hopeful Mob touching his shishou while he sleeps♡ Really made me want reimob where Reigen's cock slips out while they're kissing too much and they gently but hastily put it back in...

A Different Kind of Lesson is a ton of joy! Mob with a high libido is fun to see, and he's also very adamantly anti-condom (lmao). A very blunt Mob is good to have now and then.
Awkward Firsts, Seconds Next is so cute too...Reigen's impatience killing him while Mob keeps being nervous and drawing back is so clumsy and cute...*Mob jerking Reigen off to cum inside him...*begging the other to hang in there so they can cum together...gripping my head I think I hauve covid

kisses for beginners is cute!! I love when text in Reigen's POV is messier and quicker than normal, like his talking style! I want to think about reimob first kisses more...
//Self-harm> Come Out of Your Shell is a rarer one for me, since I don't really vibe with self-harm, but I like hurt/comfort. Mob's growing shock and upset at them existing, and the following, desperate little wound kissing to make it better is sweet.

They're as-is art from the (long-dead) mobile game Psychic Puzzle! Which, while a canon product, doesn't always match the canon of anime/manga either by timing (choosing color schemes for characters that hadn't been in the anime yet, like the Minegishi/Hatori/God Ekubo) or to make a visual gag.

In canon Teru is usually between well-defined to ripped as hell. There's not a lot of the others besides Mob that can be compared — The onsen artwork doesn't show them below chest, the cancelled summer OVA stuff has Ritsu and the adults clothed (Teru's well-defined, Mob's soft), the artbook shows only some of Mob's stomach (soft), the summer omake is doodlier than the manga and can't be referenced.

(Going to personal beliefs here: Ritsu's good at school sports, but he's not interested in exercise or muscles like Mob is, so while a fun gag on the whole "Mob is not as buff as he dreams and everyone else is more built" I think he's only a little more defined, max. Definitely not more than Reigen who's an actual adult and surprisingly defined when ONE drew him.)

But yeah TL;DR with the evidence we have Teru's among the most muscular, Reigen's semi-defined and Mob's the softest (Ritsu's a mystery)