In CharlieSpeak, 'open' now means naked. The boy is clearly a fan of 'open'.
The other day, after an attempt at going potty, he was lolling on the couch buck-open,alternating between waggling his heinie all around in the air and sitting with his head hanging off the bottom of the couch and his feet sticking up from the top. I went to dress him and he protested, saying, "No! I open!"
He gets very angry when asked to wear clothes, especially when he loses access to his 'button'. If my navel were that cute, I would probably feel the same.
I'm getting him into jammies last night and he keeps pointing to his shirt, saying, "OPEN!" When realize what he wants and ask, "Do you want me to take your shirt off?" he responds with, "Yes. I open. I sleep like man."