I'd love to see a story where Joe and Booker get up to some sort of bro hijinks that no one else on the team would ever deign to join (I'm thinking in some nebulous future where Booker has earned forgiveness, Quynh is back, and Andy is still immortal). It's a buddy comedy situation, but with unexpected feels as Booker has learned he needs to actually talk about his feelings if he wants to be understood and supported in the way he needs, and Joe deals with the murkiness of loving a brother who has hurt you. Maybe a serious talk, which they've put off for far too long, just bursts out in the middle of some truly wacky situation.