naughty words and more questions from a 3 year old

We have been lucky so far and Josh hasn't learned any truly naughty words, but he says some that he thinks are naughty. A while back Josh was calling us "Baby Bottom" and we decided to bring up the subject of naughty words. We told him that wasn't a nice thing to call another person and we weren't going to use it. He eventually forgot about baby bottom, but it has resurfaced. I don't know why, but he has started using it again. Last night while I was changing Lucas's diaper I said something like "Lucas, you have a very stinky baby bottom!" and Josh just chose to hear "Baby Bottom". He said, "Awww, Mom! You said baby bottom!!!" Then today in the car after a nice lunch at First Watch with Richard where people actually complimented us on our cute kids, Josh starts with baby bottom again. We are saying goodbye to Richard and dropping him off at work while Josh is saying baby bottom, baby bottom, baby bottom over and over again! Argh!

more questions from a 3 year old...
How do frogs hear? (he is very observant and has noticed that frogs don't have ears)
How come my eyes can't see my face? (think about explaining that one for a second)

As you can see, with Josh around I am challenged with my teaching skills every day. I don't really think I am taking time off from my career. I am getting full-time continuing education!