We were in the car he spotted a random black man walking his dog and exclaimed, "That must be Granddad!" Of course, this is my fault for not submitting him to enough cultural diversity. Thus followed an explanation of skin colour and the fact that there is more than one black man on the planet.
Now, the public declarations regarding the state of his privates or toilet functions? They're the most challenging. I took him to Legoland at the weekend. There was a particular ride he said he wanted to go on because it made his 'peanuts feel funny'. He sat in between a dad and a little girl. The dad must've cursed about his nether region, because my son was there, springing up and down, yelling at the top of his lungs "GONADS!!!" repeatedly. I was watching with my sister and a couple of parents who were giving me sideways glances. However, when I did get the chance to ask him what he had been yelling he innocently responded with, "Doughnuts". I'm not sure if that's much of an improvement.
In a pub recently was his finest moment (and my worst). He asked me how to spell 'or'. Little did I know that this was part of a longer word in relation to the drawing he had just finished: