I had to tell him

Last week, Caden had to give a blood sample at the doctor's office, so his finger was sore where they extracted blood (he was concerned that they weren't going to put the blood back in, but I digress).
We went for a swim that night in our neighborhood pool, and he didn't want to get it wet. So there he was, swimming about, one middle finger sticking up. This is a bit tricky, mind you, as he can't touch the bottom in some of the pool, but he was quite persistant in holding it out. I might have let it go, but there were other families at the pool and I didn't want them to think we were subtly trying to get them to leave!
So I had to tell him that sticking up your middle finger is a rude gesture. I always feel a little sad when taking a bit of innocence away, but I felt I needed to! So then he went to swimming about with 4 fingers up. That was better. And we may have a chance of making friends here.