He is 3.8 and his trousers have never developed holes in the knees.....until this last month. He has ruined 3 pairs of trousers in as many weeks (they are all oldish ones but all seem to have gone at the same time ) and unfortunately they were all his fave ones that are no longer available in the shops.
It is going to cost me a fortune if he carries on like this - how do boys do this???