Dish washing session

Ben (my 5-year old young little friend helping me filling up the dish washer):Why are we putting the water glasses in the machine?
Me:Because there are dirty.
Ben:There are not REALLY dirty as there were filled up with water.
Me:Good point. But you forgot about ladies' lipsticks that needs to be taken off.
Ben:Hmmm...
Me:Is it ok with you?
Ben:It would be easier for the machine if ladies were not wearing lipstick - but I heard you and mum laughing in the bathroom when you were putting it on so I guess it makes you happy so I don't mind.