The mercurial Frank O'Hara...

-  this is how I understand the story -  loved his friends, loved to party, loved to eat, drink and smoke, loved to debate and discuss, score points and win the argument.

John Ashbery, his good friend and mentor, was older, more fragile I surmise, more easily hurt...
Wounded by Frank's sharp tongue and mistaking his friend's clever words for a cooling of their relationship, he withdrew a little, in self-protection.

Frank's response? To 'unfriend' or 'block' him (or the 1960s equivalent)? Far from it - O'Hara wrote what is to me one of the loveliest tributes, in his poem  'To John Ashbery':

"I can't believe there's not another world
where we will sit and read
new poems to each other,
high on a mountain in the wind.."

Frank O'Hara died ridiculously early in a freak accident at the beach. John Ashbery survived all the 'school' of poets and lives still with their memories