Does anyone know the deal with "Our Lips are Sealed"?

I wasn't alive when it first came out, and I'm out and not wanting to Google, so does anyone know the story with the Go-Gos and the Fun Boy Three versions of "Our Lips Are Sealed"? I'm left wondering, because of the Hilary and Haillie Duff version, since there's no response, are they singing it at each other, and if so, eww.
Also, I have to conclude that it's a good song at the core 'cause otherwise I wouldn't find myself liking their cover.