Help me find a song?

I’m trying to pick a song to serve as the “soundtrack” to a certain aspect of one of the games I’m in, and I’m coming up empty. So I turn to you, o internets, for recommendations!

The thing I’m trying to set to music is a situation where two character who both have a crap-ton of secrets (including false identities) are going through kind of a fencing match/cat-and-mouse game of figuring each other out and maybe developing something resembling trust. In a perfect world, the song for this would be a male/female duet, but that’s icing on the cake if I can get it; mostly I just need a song that fits the concept. Or, if I can’t get suitable lyrics, something instrumental that is both lush and a little playful. (With a library of over 17000 songs, you’d think I would be able to find something that fits. But nothing has clicked: the closest I’ve come is “Qué Viyéra,” which still isn’t quite right.)

Any suggestions?

Originally published at Swan Tower. You can comment here or there.