John, Paul and The Erection film.
I didn't know that this was how Paul had found about that film. Neither did I know that Paul had found himself astonished and angry about it. The implications can be too many, of course.. I'm not saying that it was jealousy or possessiveness. By the way things were at the time it's pretty possible that it was mainly that he was angry because of the repercussions that may have, as in an impact on the band. I'd like to think that it was a little bit of both, to be honest.
"Hanging around Apple at the time it was impossible not to be aware of the daily tensions. There were tears when one of the old Liverpool mates was sacked by Allen Klein, with no intervention to save him from the Famous Four; paranoia during Derek Taylor’s Olympian damage limitation exercise to the world’s Press when John and Yoko were busted; and astonishment and then anger on a Beatle face when it accidentally fell to me to tell Paul that John had made a film of his penis in slow motion, before, during and after erection. The film was called, naturally enough, Erection." - Connolly, Ray (2011-05-22). The Ray Connolly Beatles Archive
We know that he wasn't very happy either when he found out about "Two Virgins", precisely for the impact that it could/will have on the band, yet he managed it quite well.
ETA: This paragraph comes a few pages later:
For Paul, considering what was going on around him and John’s iconoclastic determination to destroy the Beatles’ former image, it now seems that only frantic work could assuage the pain of seeing his world collapsing.