Sneaky...or not?

I am sure many parents are like us in that when we put our kids to bed, then we pull out the ice cream and watch a movie. We think we are being sneaky and what our kids don't know what we are doing the better! Well, last night we put Everett down and then pulled out the ice cream and went to start the new movie we bought in town earlier that day. I decided to check on Everett since he hadn't peed yet before bed and he told me he needed to go potty. So, I got him in the bathroom and on the pot and this is our conversation:
Everett: "Where's daddy?"
Me: "Over there." trying to be as vague as possible.
Everett: "Daddy working."
Me: "Okay" Just going with the flow
Everett: "Daddy watching new show."
Me: with deer in the headlight look on my face I say, "What?" not sure I had heard him correctly.
Everett: "Daddy watching new show."
Me: deer in the headlight look on my face continues

We get him back into bed a like 10 mins later he comes and says he needs to go potty. We are watching the movie at this time and he didn't come into the front room and he could barely see us. So, I take him back to the bathroom and he is sitting there. We hear Rex clanking his spoon in his bowl and another conversation starts:
Everett: "Daddy eating ice cream"
Me: Same look as above is on my face and I say, "What?"
Everett: "Daddy eating ice cream"
Me: "How do you know?"
Everett: He changes the conversation
Side note: He isn't going potty. He just doesn't want to go to bed.

He goes back to his room and a few minutes later he comes back, naked, and says he needs to go potty. I tell Rex that he has this one and he takes him to the potty. Meanwhile, I take our dishes to the kitchen and am rinsing them off. Here is dad and Everett's conversation...
Everett: "Mom eating ice cream."
Dad: "Mom doing dishes."
Everett: "Mom doing ice cream dishes."
Dad: bursts out laughing

My question...How does he know these things??? We've tried to be sneaky about it, but somehow he knows. What a funny kid and smart I might add!