Don't watch.
The whole film could have been condensed inti a 30 minute short film, this was over 2 hours of nothing! The trailer for the film was much more exciting than the actual film.
I believe it was meant to portray toxic masculinity and homophobia.... I feel it didn't really manage to do this at all. Phil (portrayed by Benedict Cumberbatch) was a bit of a dick to his unlikeable brothers unlikeable alcoholic wife and son. Lots of use of the word unlikeable but honestly no other way to describe these poor characters. The 4 main characters spent a lot of time just moping about with miserable faces not really doing anything or interest or consequence.
The only slightly interesting part was at the very very end when you find out Pete has murdered Phil. And even that could not have been more boringly portrayed.