So I asked Isaac if he had cut his hair. He said, "Yes."
I couldn't figure out when it had happened or how. When I let the boys have scissors I watch them like a hawk. If I didn't I would inevitably find curtains in tatters or a piece of furniture shredded beyond recognition.
Then suddenly I realized that he was in our kid-free zone unsupervised.
Aha! He fessed up that it happened in the front room the night before.