Stefun Darts is not your typical college student. Instead of going out with friends or splurging on himself, he saved his money from his full-time job to fulfill an act of generosity he'd planned for years in secret. With $15,000, he paid the remainder of his grandparents' mortgage and sent them on a vacation to the Bahamas. His motivation: to show his appreciation. His reward: their tears of joy. Watch the surprise unfold in this video!