Out Smarted by a Four Year Old....ALMOST!

So, my son is now 4. He is very smart. Today he has begun trying to used words to trick me. The main one went like this...

M: Did you want to go swimming today?

E: Yep. I can go swimming today?

M: yep.

E: I didn't poop in the pool?

M nope, you didn't so you can swim today.

E: Cool. I can poop in the pool today.

M: Yep, you can...wait...you can swim. You can't ever poop in the pool.

E: Gotcha mom. I was just jokin'...

Another one was...

M: Didn't we tell you no throwing things down the stairs?

E: Yes. I didn't throw it down.

M: How did it get down here then?

E: I rolled it.

M:Rolled it?

E: Yep, rolled it...it's not throwing!

M: OK No rolling things down the stairs, bring it down with your hands.

E: Can we talk about this? It's easier to roll it! (Big cheesy smile to try to win me over).

M: You should be a lawyer.

E: I am not a liar!...

What will it be like when he's a teenager?