One of the males in the litter had his first erection at 7w+2d. Now he's 8w+1d and he's forever having them - to the point he will have one every 1-3 minutes out of the pen and doesn't play with the others. He's sitting down, has a little rub of his bum (and testis too?) on the floor and then a little leg shake and lick. I assume he's masturbating? He was only exposing the tip of his penis to begin with, now he's bringing out a good 5mm a couple more mm and his glandis will be exposed. Do I leave him to it or try to halt the behaviour? Could it be an underlying issue - UTI?