Yeah, get your mind out of the gutter yaoi fans. lol This is also not making fun of the characters as I just love them and I thought it would be funny to make them dance to something like this. and yeah, Roy's leading with the dancing and singing.
The ending is funny. I took one look at the when I was making some other models dance and immediately thought of Roy and Ed. It'd be funnier with these two. Sadly I have no Riza so it's WInry that walks in on them but it's still a funny thought. So pretend that the stage is Mustang's office as it's the closest thing I can find.
Read youtube video description for stage/motion/and model links and credits. (No direct downloads)