When Gary ferried Mac and I to the in-laws for Thanksgiving dessert, I asked, "So, how is Tinkerbell behaving?"
"She's a biter," Gary said, "So far she bit Mac and Moses. She hasn't bit Willow yet."
"What's Willow's secret? Does she run? Show her belly?"
"Mom says Tinkerbell doesn't like boy dogs because she was, as Mom says .... " (he whispered) "Are-Ay-Pee-e-Deed."
It took me a second. "Oh. Well, you can't make assumptions. Maybe it was consensual."