I dont usually put up with kids touching my stuff or sniffing around especially if its hot work. I simply tell the ho to call me back when I can work undisturbed.
One time I was doing an above ground pool and when I went to the truck I saw his two girls in it as I usually leave the main doors open. Needless to say my BP shot up. I called the HO from inside and told him if he cant keep his kids out of my way (while pointing to the truck with his little kids in it) that I would have to come back another day and cant promise when it would be. This was the middle of the summer, mind you and he really wanted that pool hooked up asap. I had him sign a contract and got half the money up front. He said no problem and went over to my truck and when his kids saw him they immediatly knew they were in trouble.