Talk to Urologist on Sex Problem

My brother has been married for 3 years he is not able to do intercourse. He gets normal erection. No erectile dysfunction. They only do oral sex or foreplay. He has tried it once or twice to intercourse but couldnt do it. He is mentally not ready for intercourse. And now the situation is so difficult for both of them there marriage is at risk of separation. He says mera dill karta he aik dafa ye intercourse ho jae mere liye ye imtehaan ban gya he. He has no medical history. He is healthy and active in sports too. Kindly suggest what to do? Is this a psychological issue or something else? They both went to gynaecologist for checkup. He didnt tell him any test samjhaya usko bus. We are really worried kindly help