This book is written as a love letter to his son, who has come out to him as Gay. The father, who is Gay also, is telling him what Gay Pride and a good Gay Life is all about in his opinion. He does this from his perspective as an active member of ActUp at one time as well as other HIV and other more general LGBTQ concerns.
His son, he acknowledges, is a lot younger and has grown up in a time where it seemed that the Gay Rights Movement had succeeded. But, as he points out, the reality is that there is still reason for concern, especially during the era of trump, who, by the way, came to his wedding to his husband and seemed supportive, and then became one of those most dangerous to the LGBTQ community once he got into the White House.
We are in trouble again, assuming that we were ever out of trouble. And the time to become active is not over, and he cautions his son that he also needs to pay attention and claim his gayness, including the political implications.