Kevin, Joe and Nick Jonas' youngest brother is all about bringing the good times when it comes to entertaining his nieces. That's why he’s the favorite.“I'm the fun one,” the 21-year-old said on Saturday during the opening of the Las Vegas location of the Jonas family’s restaurant, Nellie's Southern Kitchen. “I'm the guy who will get on their level and play with their toys until they ask me to stop.” And Franklin certainly has enough nieces to entertain -- with all three of his older brothers officially being fathers.