Is my what nasty?

The other day my son was doing something that really annoys me to no end that I think every member of the male species does... touching his 'man parts'. I told him I thought it was nasty what he was doing and he responds "Is your penis nasty too?". I told him that girls don't have a penis and that our private parts were different. I realized that we have not had the conversation yet about the differences between boys and girls. Being the active, typical boy William is he just sort of moved on to the next thing. My husband heard our brief conversation and starts to laugh at me. He says that maybe it was better I explain that to him since I might handle it better. MEN!