Can a man be FORCED against his will to participate in ?

The story is a guy was married, his wife was his partner in business, they divorced went their separate ways but just as he was becoming seriously involved with a new partner his ex wife re appears on the scene and blackmails him into having secret ual liasons with her on the basis of exposing fraudulent business practice that he was involved in.He is considering confessing all to his new love but fears she won't believe a man can perform if he's not a willing party.What ido you feel is the truth of the matter and what should he do?