"I hate to interrupt you while you're working," you might have said.

And you would've had every right to possibly continue, "I know you needed a few weeks of faffing time after taking those three intense seminars last term. And that road trip was probably a good break from all that research you weren't doing in the first part of summer...But it's been a while since you've been back. And now you've got something like a schedule again and a good bit of your day is free, isn't it? I'm certainly not being sexist, but...do you think you could go 'round to the grocery store?"

"For what? I just got three bags yesterday."

"For food. In case you haven't noticed, the inside of the fridge is a veritable microcosm of Beverages and More."