"So do we," Gina replied, and held out her hand, tilting it so the sapphire in her wedding ring caught the light. "Usually only expensive jewelry, though. I think it's just because they're pretty, to be honest." She shrugged, and added, "Mammals are... are a kind of animal that has live young, not eggs, and nurses its babies. Like humans, humans are mammals. So are..." She cast about for an example and came up with Skimble, their ginger cat even now probably sunning herself in the living room. "So are cats."