We arrive home and start unloading stuff from the van. I pile as much as I can onto my arms and Jo grabs a few bags and hefts Mike out of his seat. She hands a paper shopping bag with a few things in it -- sippy cups, baby wipes -- to Tom and says, "Thomas, would you take this inside, please?"

And Tom grabs ahold of the handles and starts dragging the bag up our front walk, like it's boulder trailing after a chain tied around his neck.

"You don't think he's being sarcastic, do you? Dragging it like that?" I ask.

"Oh, gosh," Jo says. "Where in the world would he get sarcasm from?"

"Well, the X chromosome for a start..."