The way I understand Johnny's statement is that after what has happened to him (you will be enlightened regarding this remark after you've read the last 2 chapters) he feels as if his sex apparatus has been severed - and so obviously once you've lost that, "practicing" would not have much appeal to you anymore, would it? :(
I don't think he attributes his lack of sex life to his mother's death.
By 1987 Johnny has become very politically aware. In days past, it was Owen who was politicized, Johnny was merely content to listen and follow like a faithful disciple. I would dare say that Owen's legacy was not only that Johnny became a Christian because of him but also that Johnny became avidly interested in the intrigues and maneuverings of the US government.
In Ch 7 (towards the beginning) John narrates:
Nineteen sixty-one was the first year of our friendship that was marred by unfriendly criticism and quarreling. Our most basic dispute began in the fall when we returned to the academy for our senior year, and one of the privileges extended to seniors at Gravesend was responsible for an argument that left Owen and me feeling especially uneasy.
So Owen was against doing the rounds of the Harvard Square striptease bars and he disapproved of drinking, and the discovery of the secret life that Tabitha had led in Boston was disquieting for him - and John especially, but I can't find the scene where they had an argument about these matters.
The school year 1961 was indeed tumultous, especially for Owen - the Mrs Lish incident, consultations with Dr Dolder, being found out about the fake draft cards, the Volkswagen incident, Mary Magdalene off her pedestal, the conflict with Headmaster White, among other things. But nowhere did I detect that these problems manifestly marred the friendship between John and Owen.
Anybody saw otherwise? Did anyone read through a passage/s where John and Owen quarrelled about these issues?

