My friend has been masturbating for a long time and he masturbate on this style like on lying on the bed without using his hand so now he is having some pain in testicles they are slightly red and there has been itching from past few days is it any danger for him in future sexual intercourse is his sperm will remain same and his size is also decreasing from the past so kindly provide me necessary information so that I could help him waiting for your answer.