Suggest Treatment For Recurrent Infection Of Penis

Hello Dr., My Penis was infected after my marriage during 2-3 days. I was treated by the Skin Specialist. I was cured properly at that time. But Now even by using the proper protection and washing the penis after every intercourse, the infection appears after every 1 or 2 months and I have take the medicin Modcef D for 2 weeks to cure it. I am not sure why it happens even after cured properly and taking care and washing the penis every time after intercourse.