Because having a newly minted kindergartner isn't exciting enough, we also decided to officially potty train Simon this week. When I'd picked him up from school a week or two ago, his teacher indicated he was ready. We decided to wait and do it after the camping trip since we didn't want to try and keep him in undies while camping when the bathroom would be so far away.
So on Tuesday morning we sent him to school in undies, and with several extra pairs of undies, shorts, and socks for the inevitable accidents.
He came back with two or three pairs of wet shorts the first day, but was fine the rest of the week, only having an accident on Saturday morning. He's still pretty reluctant to poop in the potty and holds it in until he absolutely can't anymore, but the good news is he is indeed pooping in the potty and hasn't pooped in his undies all week.
We still put him in pull-ups for nap, night, and any outings until he is more reliable. But for the most part, he is now underwear boy!