Rusty has been doing GREAT with potty training! However, the past 2 days or so he has started this new thing. He will go to the potty pad and start to pee then start walking away from the pad, while peeing

. I don't know why he is doing this or how to stop it. But after he is done, he looks up at me and is like
mommy, be proud of me i pottied on the pad 
Please help! When i see what he is doing i'll pick him up and put him on the pad and say potty. But i don't always catch him in the act.