I used to paint DS's - he would ask me to paint his when I was doing mine. No problem.
Now he's at school I would remove it before he went as no kids are allowed it there, boys or girls. I would still let him have clear polish though if he wanted it.
Now he comes to the salon with me when I get my shellac mani pedis and he is allowed to pick the colour. He doesn't want his done any more though. I have had some very out-there fortnights of colour in the past year or so!