I have been suffering with paruresis from about 25. Around 20 yrs on, i told a friend about a year and a half ago and have never told any family, girlfriends etc.
I had been in touch with Andrew and seen the paruresis board for about 3 yrs regularly getting the emails of workshop dates before i attended the workshops as i too felt uncomfortable about talking in a group but i was so fed up of suffering that i would rather of felt uncomfortable at a workshop for 2 weekends than i would feeling uncomfortable the rest of my life living with paruresis.
It is unlikely your boyfriend will be able to fix this on his own as there is much to learn in the workshops and it would certainly be a quicker and more positive benefit to your boyfriend if he signed up to this message board to begin with and read other men's experiences. He can also post any questions and nobody will ever know it is him as he will only have to put his first name on the posts so he will be safely anonymous.
The next London workshop will probably be in September and the Manchester one next January so it will give him time to build up his confidence to attend a workshop.
I went for therapy once and the counsellor didn't understand and was useless but Andrew and the paruresis trust do understand and are very useful indeed.
Men have this condition for various reasons such as past abuse, size issues, or just the way they were brought up about privacy so whatever category he fits into he will be in the same boat as others so no need to feel any shame or embarrassment.
Good luck in getting him to seek the ukpt's help.