Kendall Jenner has nothing to be "sorry" about. The 21-year-old model took to Snapchat on Friday to share a sexy snap of herself rocking a red thong swimsuit. WATCH: Kendall Jenner Attends ASAP Rocky's Cannes Show, Kourtney Kardashian Holds Hands With Younes Bendjima In the mirror selfie, Jenner lifts up her suit...