My MIL is staying with us to help take care of DD for a while. We've been showing her around the house, and the routine we've set and the most effective ways to do various things including diaper changes. Grandma volunteered to do a diaper change, so DH went along to make sure she found all the supplies and such. I'm in the other room and this is what I hear:
DH: We usually try to swap out the diapers as quickly as possible because she might poop in between.
MIL: I remember how to do this, I've got 2 other grandchildren.
DH: Well sometimes if you leave her uncovered she'll...
MIL: <yelp>
DH: Yeah, that's what happens.
<laughter>