Duty to inform lover's husband of STD?

From a story in Law.com: A man who says he contracted a sexually transmitted disease after his wife had an affair with her allegedly infected psychiatrist can bring a negligence action against the doctor, a state judge has ruled. The man, [...] claimed that Dr. [...] had a duty to warn him that he had herpes simplex before having unprotected sex with Levine's wife. I have no problem imposing liability, but doesn't this sound just a little odd? So the plaintiff is saying that his cheating wife's lover should give him a call before he sleeps with the wife to let him know....? I wonder how that call is going to go... "Hello, Mr. Doe. This is your wife's doctor. I am pretty sure I am going to have sex with her tonight. Just thought I'd let you know... Oh and by the way, I have an STD. Have a good day now....." Also, given the quoted language, I have another question. Suppose the good doctor had used protection. Would that have elimanted the duty to make the call?