so, does the single mean the one with guy singing in it too, or is there a single (aka longer ver.) of Changin without the guy? I was just wondering what the official single version was.

The standard version is the one with the guy singing too. The one with Stephanie singing both parts is on the single, too, though, iirc.

I like the one with Stephanie singing the whole time better.

yeah, I don't like the guy singing parts of it, it doesn't sound right. I'm glad there's a ver. where she sings all of it.