Entirely because of this post by @samwell-womens-hockey. Tango asks how long Bittle and Jack have been together.
He’s not trying to snoop, it’s just there. When he asked for a closer look at the Jack Zimmermann OYO figurine Bitty told him to feel free and turned back to folding his laundry, so now Tango is holding the figure up but he got distracted by the calendar. It’s right behind the mini Jack, so it’s not like he was looking for it, but all those hearts are pretty eye catching.
“Is this your boyfriend’s birthday?” He asks, pointing at the little cake drawing. It’s pretty cute, actually.
“My what now?” Bitty says, almost casual except that he’s stiffened up, fingers clutching into the sweater in his hands, and Tango really stepped in it this time. He’s always asking stupid questions and it’s not the first time he’s said the wrong thing and someone needs to put a sock in his mouth.
“Oh, uh, I-” he stutters “didn’t mean to assume that you’re… I just thought that-”
“Hush, Tango,” Bitty says, taking pity on him. He doesn’t look angry or upset, but his smile is definitely forced. “You didn’t assume wrong, ok? Now go downstairs and get those sheets from the dryer.”
So he goes, because now that he knows about dibs he’ll do anything if it means he doesn’t have to live in those smelly dorms next year, but as he’s struggling to fold the fitted sheet he wonders why Bitty avoided the question.