Hello I really appreciate your concern This can be caused by number of reasons like dryness of vagina or lack of lubricantions, infection or inflammation of the penis or at times it might be related to allergic reaction. Masturbation may be contributory factor in it. If you can provide me more details like medical history like if you are having diabetes or liver disease Similar complaints in past, I will be able to guide you better. If I were your treating doctor, I would have advised you to keep it clean and apply antiseptic ointment if it doesn t improve or worsens than I would have ordered few investigations like blood for hemoglobin, CBC Liver and kidney function test, blood sugar and urine culture or an ultrasound if need be. you may require a course of anti allergic or antibiotics drugs under supervision of doctor. Thanks for your question Wish you both good health