You had me at "You be my princess, and I'll be your toad." Here's Jimmy Fallon and Selena Gomez performing a duet version of the greatest love song ever written: Mario Kart Love Song by Sam Hart.
Sam who? Just the most awesome YouTube singer songwriter ever, yo! Check out the original song below:
Hell, even if you prefer it as a comedy song and not a sincere love song, it's better played straight. Jimmy Fallon is likable enough, but man he's ruined more than a few jokes by being unable to play a straight man who doesn't crack up.