This is mildly embarrassing, but I've been misunderstanding a common slang phrase for as long as I've known it. The phrase is "butterface," which is a rude way of referring to a woman with a nice body but a not-so-nice face. (Not sure what the male equivalent is.)
I'd thought it was making some comparison to actual butter -- does that mean she's greasy? Or mushy? Or that she goes well with toast? Every once in a while I'd hear it on the radio and went over the possibilities in my head, but in the end, I figured it was a reference to some pop culture thing that I just didn't get, being on the custom of old-dudeness.
The other night we went out to get ice cream, and Barb mentioned some woman with a cute body. The woman walked past and (being a good husband) said, "You're much cuter than her. She's a butterface."
"Someone who has a nice body but not a great face. I don't quite get what it means, how a face is like butter..."
She started laughing, "But her face, get it?"
"Oh... yeah," I said sheepishly.
"Now you have something to blog about," she said.