On tonight's episode of 'The Voice,' Cee Lo Green chose an unconventional song for the final battle round for his team in the form of Lady Antebellum's 'Need You Now.' That's right. Cee Lo went country right before the live shows start. His two remaining battlers went romantic, though. More on that in a second.

'Need You Now' was the right choice for country crooner Curtis Grimes and a challenging one for tattooed rocker Emily Valentine! Grimes and Valentine have become fast friends, with Valentine even confessing to nurturing a crush on the country boy to PopCrush weeks ago; but all is fair in love and vocal wars on 'The Voice.'

Grimes and Valentine went voice-to-voice, but before they got in the ring, Cee Lo reminded them that this love song needs to deliver a little tension when performed, in order for the emotion to come through and to connect with the listener. Cee Lo told them to take the chance and convey the passion and share it with people, win, lose or draw. Since Valentine was crushin' on the 10-gallon hat wearing Grimes, she employed the strategy of trying to make him fall in love with her through the song.

There was a detectable tension on the stage in the way Grimes and Valentine looked at each other and how they maintained a bit of a sizeable distance for the first chorus and verse before coming together in the bridge and final chorus. They even made out and shared a big, fat kiss at the end of the performance!

What is this, Scotty McCreery and Lauren Alaina during the 'American Idol' finale? The pressure of live performing on TV must aid in elevating sexual chemistry and tension between competitors. It's a natural aphrodisiac.

Coach Blake Shelton said it best, when he joked "Cee Lo probably told y'all to duet, not do it!"

Cee Lo eventually chose Grimes to move on. But perhaps Grimes hasn't seen, heard (or kissed) the last of Valentine.

Watch Curtis Grimes and Emily Valentine Perform 'Need You Now' on 'The Voice'