Rihanna - Collaborating on "Cake"?!

Rihanna's been talking about releasing the interlude on her album, "Birthday Cake", as a full song.  And from many tweets, people have gathered it would be on her birthday, February twentieth!  That's only 15 days away!  But, she doesn't care about time restraints!  Also it looks like it could become a single! She just tweeted:

Would yall be mad if Birthday #CAKE became a single?

Now here's the trick question! #IF I put collaborator on it, who would u wanna see lick the icing off????? #CAKE

COLLABORATION!  I would love to see a female on the record like Katy Perry, Britney Spears, or Nicki Minaj, but my guess is that it would be a rapper.  I would love to get some mad girl power on this twerking jam!  Who would you like to see featured?  Tell us in the comments!


UPDATE:  Could it be Christina Aguilera!?  Rihanna Tweeted:

I need somebody #DIRRRTY on my Birthday #CAKE ;) lol

Xtina did have the song "Dirrty"!

UPDATE: Rihanna just tweeted:

And please!!!! No girls allowed on #CAKE

Looks like it will be a male on "Birthday Cake"!  Maybe Eminem!  That would be hot!