Mid-coital testicular pain strikes out of the blue

Eric, a 75-year-old male, presents with pain during intercourse.
He has a lifelong history of a retractile right testicle, and is experiencing new discomfort due to blunt trauma to the testis during the thrusting of intercourse.
This discomfort is causing such disruption that he has resorted to tying a rubber band around the scrotum during intercourse to keep the testis located in the scrotal sac.
The retractile testis has been present for as long as Eric can remember.