They both complain that he is suffering from ED. The doctor asks the man to step outside, so he leaves.
He then asks the wife to take her clothes off. She asks why. He says he needs to check something that might help her husband get an erection.
So, she strips off, lays down on the table and the doctor walks around her a couple of times and writes some notes in his charts. He then tells her to get dressed.
The doctor walks out and says to the husband,
"It's not you, she doesn't get me hard either!".