Hi and thanks for the query, I suggest he deserves a critical clinical evaluation. Testing for diabetes is very vital in this case considering the fact he pees frequently. Diabetes could have implications as far as the erectile function is concerned. A detailed urogenital assessment is necessary also to exclude a urinary tract infection. The opinion of a urologist is indispensable for this particular situation. A good psychological state, courage, motivation, adequate pre penetration excitation are also prerequisites for an exciting sexual experience. While waiting to consult his urologist or Sexologist depending on the case, I suggest a rich diet in fruits, vegetables and exercise as he books these respective appointments for evaluation. Best regards, Luchuo, MD.