Hello and thankyou for approaching DoctorSpring with your query.
I have gone through your case and understand your concern.
I understand that your son is hesitant to visit the doctor, but I would advise you to try and convince him as it is required that he should get examined.
He has got a condition called phimosis where the foreskin cannot be fully retracted from the glans penis.
Non surgical interventions like applying a topical steroid, or stretching exercises can be tried depending on the severity of the phimosis.
Circumcision is the treatment of choice, and it is safe to do even in his age. It is conducted under local or regional anaesthesia and is very effective.
Hence I would advise you to try and convince your son and visit the urologist.

I hope this has helped.
Feel free to follow up.
Thankyou.