Just to get the question out of the way…yes, that is a man dressed as Janet Jackson! He or she or it goes by the name of Britney Houston; a dancer who likes to perform little spoofs a popular videos. Go check the YouTube page.
I would just like to know what “Britney” does for a living. I mean, in my eyes if you have time to go about re-creating an entire music video like this, from the costumes to the settings, you must have a very uneventful life, otherwise. The shit is funny, though!