I forgot the rest, but my mind produced the idea of Paul getting drunk outta his mind and clutching Stuart's bass after he's left the band for good, sobbing. And somehow Stu himself being the one to wrangle his sorry arse out of the Cavern's backstage and back to his home, all while Paul whines that Stu will never love him because he was such a dick to him and that the bass is the only thing he'll ever have from him. Stu keeps telling Paul to calm down and Paul genuinely doesn't recognize him from how drunk he is and just keeps angsting and saying how he'll never be able to apologize and make things better.
(Also, when they do get to Paul's house, his dad is there and just looks at his fucked up son up and down, tells Stu to take him to his room and don't do anything sketchy, and goes back to sleep.
Couple days later Stu shows up again to have a serious talk with Paul and Mr McCartney drags him by the collar to Paul's room, where he hasn't stopped crying since that night, and tells him very sternly to 'fix this'.
Man's just relieved that his boy picked the tranquil artsy dork and not the rebellious disaster on two legs that is John Lennon).