After five years of dating, John Cena got down on one knee and asked Nikki Bella a life-changing question. Of course, he had a special accessory in his hand when he asked the WWE star to be his wife Sunday night at WrestleMania 33—a nearly 5-carat sparkler. According to certified Gemologist Appraiser Deborah Villepigue, the ring is classic Tiffany & Co. "The center stone is a perfect, round, brilliant diamond around 4 1/2 to 5 carats and about 1/2 carat of round, brilliant diamonds flanking the center stone on the band," she described. "All the diamonds are set in platinum in a classic, six-prong platinum head. It's a classic Tiffany design. The center diamond should be Vs-1 in...