Stray!Jason Robin!Tim au where they're kids making a ruckas and tussling then some loud expensive car rolls up to a stoplight blasting this song:
And they stop fighting to sing along for a second then Tim tries to do the whistle and fails and Jason laughs at him bc "what kind of bird can't whistle???" Then mockingly does the whole whistle at Tim
Then the next time Tim sees him he proudly shows Jason that he can do the whistle from the song too!!!
And it becomes a little inside joke/ call and response between the two of them. And Batman is just sitting there with his head in his hands because he knows that song isn't ACTUALLY about a whistle. But he can't stop their joy now.
So everytime one of them starts with a little "dodo-do-dado" the other HAS to whistle back the "do-do-do-dado" to prove they can.
Then Tim dies by the Joker bc the Joker ALWAYS kills the second Robin for the angst, and then he's alive, and then he's back in gotham.
And then he and jason have the big "oh my god you're alive Tim" thing and they have "fuck I can't belive it's you" sex. And then afterglow. And then. Jason bursts out laughing.
And Tim's like "what????" And Jason just barely gets out the first notes of the whistle through his laugh and Tim awnsers back with his half of the whistle and Jason's back to cackling and Tim is still oblivious.
And Jason gets himself together for long enough to ask Tim "Will you blow my whistle, baby bird???" And Tim flushes and realizes that oh my god they TOTALLY didn't get that innuendo, and their entire childhood was a REFERENCE to the innuendo. And then he also busts out laughing bc "Oh my god."
And the fic would be called "Whistle, Baby."
