Here, have some Zimbits headcanon:
I think the thing about Jack Zimmerman is not that he’s bad at keeping secrets. He’s great at keeping secrets; what he sucks at is hiding it when he’s happy. He’s got lots of practice making himself seem happier than he is, but he hasn’t really had to worry about it the other way around. And he’s in love, man, and Bitty’s in love back, and he’s playing good hockey, and basically his life is awesome, and so maybe that results in him being a bit smilier than usual.
And let’s face it, hockey players live in each other’s pockets during camp and the season. Don’t you think someone would have noticed something, a text that comes in while Jack is in the shower, or an awkward non-answer to a perfectly innocent question? And so unnamed teammate is talking to one of his bros who’s on another team and played with Jack in junior and mentions that he seems like a cool guy, he wasn’t sure after all he’d heard, but Jack’s really nice, always smiling and laughing, and the bro is like lol wut, Zimmerman must have been replaced by a pod person. And so that’s odd, but people do change, and it’s always nice to see people enjoying playing hockey so much.
Anyway, what I’m saying is that Jack is the least subtle dude ever about this stuff, and pretty soon it becomes an open secret that Jack’s with somebody and it must be a guy otherwise he’d talk about it. And a few seasons in when Jack calls everybody together and gives them all a stilted speech about how he’s gay and he wanted to be honest with his teammates and how he’ll understand if they feel upset, they’re all “OK, and what else is new,” and Tater says “yes, yes, we know, we love you always Jack, can we meet your boyfriend now, I hear he is good cook.”