I have this same "problem" with my 2 1/2 year old son...his hand it ALWAYS down his pants. I agree with some of the others that you don't want him to think it's wrong to exlore his body. I just tell him that it's n ot nice to touch his "wee-wee" when other people are around, only when he has privacy (he knows that privacy is what you give people when they use the potty!!) He usually takes it out. I think it's totally normal...I wouldn't worry unless he is still doing it in 5 years!!!