Name of song and artist please...

I'm not sure about the name of this, but here are the lyrics: (a guy sings most of them and then a woman sings some verses) it's malso fairly new.

Mystery girl, whoever you are, ... all alone... it's you that I want, mysterious boy...etc.

Any ideas?

Promiscuous Girl, by Nelly Furtado?

That's it!
Thank you sooo much! I'm surprized you figured it out with such little lyrics, most of which were wrong.

Cheers!