Review Question - QID 108290

A 40-year-old male visits a urologist and reports that for the past 2 weeks, his penis has been gradually curving to the right with associated pain during intercourse. He is able to have a normal erection and he does not recollect of any trauma to his penis. Although he is married, he admits to having unprotected sexual relationship with several females in the past year. His vitals are normal and physical examination in unremarkable except for a lesionless curved penis. It is painless to touch. Test results for sexually transmitted disease is pending. Which of the following is the most likely cause?