Sir/Madam,my son(20 years old) shares everything about himself freely.Recently he showed me that when he has a flaccid penis he s easily able to move his foreskin over glans and as soon as he got an erection(13.5 cm) the foreskin is moving only half of the glans and when he tried to pull it forcefully it slightly hurt him and when he left the foreskin it fell normally onto the glans of his penis.even he had an erection of about only 80-85 degrees erection and he said that the first he moved the foreskin back(when his penis was flaccid) was 5 years back.will it take some time to get foreskin get stretched and automatically move back onto the glans????.is the angle of erection in normal range or there is any problem??? because when we saw on internet we found that erection was above 90 degrees usually and as soon as man gets an erection the foreskin automatically moved back without any hand job.i asked him whether he s masturbating?? and he said that he does it 7or 10 times a week....as masturbation is not harmful should i ask him to masturbate much so that when he moves his foreskin front and back it may get stretched properly and also i found very very light brown colored patches(2 or 3) on his scrotum and is the length of his penis and angle of erection normal????should i ask him to stretch the foreskin by fingering ... please please suggest any remedy so that my son has proper erection and reduce his disappointment...