welcome to HealthcareMagic
The problem you are having is pain while having sex as the skin is not coming completely and the glans penis
is not getting open.This condition is probably because the skin is not retracting properly and the solution is surgery to remove the skin and it is called circumcision
.If you want to avoid surgery you can try lubricating jelly like K-Y jelly
or Lubic jelly that you can use at time of sex for lubrication.If that does not help then you will have to go in for surgery.