A double WHAT?!?

We were in the car, listening to the radio, when Carrie Underwood came on. Her song: Undo it.
Being the "undiscovered" American idol that I am, I was singing along.
When Hubby asked:"Who is this?"
I gave him a look that said, Seriously? You don't know who this is, have you been living under a rock?
"It's Carrie." I said finally, choosing a part in the song to stop at because I wasn't sure of the lyrics at that particular point.
"Underwood?"
"Um, hummmm." I needed to get back into the song the chorus was coming.
He said something to me that sounded to me a little like a foreign language, which stopped me dead and I asked: "You just said like two words that I have never in my life heard before."
He repeated himself: "Carrie is singing double entendre stuff now?"
"What? What is unTUNdrey?"
"Entendre. It's french."
"Yeah, ok what does it mean s'il vous plait?"
"Basically that; it has a double meaning, one being s-e-x-u-a-l innuendo." (he spelt sexual because we had little ears in the backseat.)
"What are you talking about?" As I'm thinking about the song and how he could possibly think there was something risque' about it. She got in a bad relationship and she has regrets...
Now it was his turn to give me a knowing look.
"Sara, ah ah ah ah DO IT?!"
I started laughing. First of all, she is NOT moaning, and and second, he could never pull off a fake, you know, he just sounds stupid. He's no Sally...
I said "It's not Ahhhh." demonstrating my acting skills, "It's UN. UN do it, like undo your seat belt the opposite of DO. UN."
Now he starts laughing, "Oh, that makes more sense." And then he quietly sang it to himself, as if to put it all together.
I say to him: "You know this is going to end up on the blog right?"
"Uh huh, somebody has to be your muse."
"True."