Jack getting Bitty a plaid shirt (just like his one that Bitty stole and wears constantly) for Bitty’s birthday, and Bitty’s happy about it, but he’s just not as excited as Jack
expected wanted him to be. Jack doesn’t get it. “Because you wear mine all the time,” he explains, and Bitty confesses that he only likes wearing it because it smells like Jack, not because of the shirt itself. So Jack goes to take it back after apologizing, but Bitty wants to keep it because it was a gift and it’s a gift from Jack, so of course he wants it.
(He doesn’t wear it nearly as much as the one he originally stole from Jack and Jack notices)
So next year for Bitty’s birthday, Jack gives him seven shirts and tells Bitty to smell them, but Bitty doesn’t need to to know they’re all going to smell exactly like Jack coz he’s seen Jack wearing them throughout the year. And this is so much better because not only does each shirt smell just like Jack, but each one has a story.
The grey t-shirt with the rip in the right shoulder from when they were walking to the murder stop-n-shop and Bitty tripped on the sidewalk and grabbed onto Jack’s sleeve for balance.
The red plaid shirt without pockets that smells a bit like maple syrup and still has dried pastry on the cuff from when Bitty and Jack spent an entire day baking pies for Hausgiving.
The white button-up which dwarfs Bitty when he puts it on, but reminds him of Jack and his half-year anniversary date at a fancy restaurant (though the best part was after, when the shirt lost two buttons to Bitty’s scrambling fingers and Jack’s impatience).
One of Jack’s Falconers jerseys (Bitty has four now), a sleep shirt, another plaid shirt (blue and grey), and a gag t-shirt proclaiming “kiss the cook” which Bitty has been confused about Jack buying for himself and wearing voluntarily the entire year but now it makes much more sense. (Whenever Bitty wears it it takes him twice as long to bake anything because Jack insists on kissing him whenever he reads the shirt, which he makes sure to do often).
It becomes a thing then, buying clothes with the sole purpose of exchanging later. Sometimes they get matching clothes so the swap isn’t that noticeable (though the sizes are always an issue).