My child is a Monty Python Skit

The Scene: Wild Boy and I are getting ready for bed. He keeps refusing to admit that it is nighttime or that it is bedtime or that I will be leaving his room shortly.

Me: "I'm going now."
WB: "No, you're not."
Me: "Yes, I am."
WB: "No, you're not."
Me: "[WB], don't contradict me."
WB: "I'm not contradicting you."
Me (mustering patience and failing): "When you say the opposite of what I'm saying, you're contradicting me."
WB: "No, I'm not."