Cute new couple Joe Jonas and Demi Lovato didn't just make a splash during their duet on last night's"American Idol," they made a "Wave." The beloved-by-tweens duo belted out their new tune "Make a Wave" together on the show and both seemed quite pleased with how it all went. Joe wrote to fans this morning, "Thanks to everyone who watched American Idol last night! @ddlovato and I had a great time. Demi posted, "What an incredible day... Thanks to everyone who tuned in to American Idol tonight!!! :)."