Dorian learns to knit, for reasons, and he does it while in the car with John on stakeouts or when they're driving places. John kinda makes fun of him for it being like "why are you knitting a hat? You don't need a hat. It'd be faster to just buy a hat." And Dorian telling John that it's relaxing and maybe knitting would help John with his anger issues. So John shuts up about it so Dorian won't try and teach him how to knit.

Sometimes Dorian knits during interrogations and it really freaks perps out like "why is the synthetic knitting!?" It's kind of hilarious how off balance it makes the people they're interrogating to have Dorian knitting in the room. Most of Dorian's early knitting projects end up going to Rudy, who just loves them - especially the fingerless gloves and wrist warmers that Dorian knits in a wide variety of colors because his hands get cold as he's working.

John walks into the break room one day and finds Stahl and Dorian knitting. Valerie tells John that she's always wanted to learn and that Dorian is a great teacher. Dorian asks John if he'd like to learn and John just flees the room. Dorian and Stahl's knitting becomes a regular thing, and John starts avoiding the break room because he doesn't want to join their little knitting club. But his anger management group therapy sessions aren't going well at all, and Dorian has been chatting Captain Maldonado's ear off about the benefits of knitting, and she ends up ordering John to join Dorian and Valerie's knitting group since he isn't going to take therapy seriously.

So under captain's orders, John finally allows Dorian to teach him how to knit, much to Dorian's glee. And he's terrible at it, but Dorian just beams at the first hat that John knits and insists on wearing it outside, and John is mortified, and it makes him determined to learn to knit better so Dorian will wear a hat that actually looks good rather than the embarrassing monstrosity he's currently touting around town (especially because Dorian has to tell everyone that John made it).

John actually enjoys knitting, and finds it really is calming and does help him with his stress levels. Not that he'd EVER admit that to Dorian, so he still grumbles every time they sit down in the break room for a knitting session. Detective Paul makes a few jabs at John when he finds out, but then shuts up when the Maldonado suggests that Paul might benefit from joining the knitting group as well.

Dorian ends up knitting presents for the Captain, Rudy, Valerie, and John for the winter holidays. He knits them each a scarf/hat/mittens matching set. Only John gets gloves because Dorian knows he hates mittens even if they are warmer. Valerie knits Dorian an ugly Christmas sweater on purpose, because it's "tradition" and Dorian loves it and wears it to work every day for a week, much to John's annoyance. John has been practicing enough that he is able to present Dorian with a hat that actually looks really nice, and Dorian gives John the extra gift of agreeing to wear the new hat instead of John's first one. John takes great joy in setting that first hat on fire, and Dorian just smiles and Valerie rolls her eyes.

Over time, their break room knitting circle grows as long time knitters come out of the woodwork, and people who think it looks interesting to try decide to take it up under Dorian's patient tutelage. Dorian ends up meeting and making friends with a lot of people who work at the precinct through the knitting group, and it makes John a little jealous when Dorian starts receiving invitations to social outings that he isn't also invited to ("you need to learn to be more personable John"), but at the same time is really happy for his friend. Dorian is a great guy and deserves to have friends.

Dorian donates almost all of his knitting projects to shelters throughout the city. After all, he doesn't really need to stay warm. When the rest of the knitting group becomes aware of the fate of most of the things Dorian knits, they end up donating things they've made as well.

The next year, Dorian receives five hand knit Christmas sweaters from people he hadn't even known the year before, and he beams so much as he shows them off to John that John can't help but smile back. John also smiles when he notices that no one has gifted Dorian with a hat, and the only one Dorian wears is the one he gave him the previous year. He gives Dorian a matching scarf as that year's gift. Dorian gives him a Christmas sweater that John wears a grand total of once to appease Dorian before it goes to the very back of his closet never to be seen nor heard from again. A picture of him in the sweater finds its way onto his dating profile anyway.