Suggest Treatment For Painful Cuts On Foreskin Of Penis

my boyfriend is 28 years old and we have been together for 4 years. Recently during sex and masturbation small paper like horizontal cuts appear on the forskin. sometimes they bleed quite badly and are painful for him. I have asked him if he is sore any other time and he says its only when he has sex or masturbates and the cuts seem to disapear within a couple of days each time