Last night, before going off on hot Valentine's Day dates, Sports Illustrated hotties Hilary Rhoda, Anne Vyalitsyna (Adam Levine's girl and video model), Irina Shayk, Christine Teigen (John Legend's girlfriend), and more stopped by the David Letterman studios. What was the occasion? To unveil the newest SI cover girl. Drum roll please, it's Cristiano Ronaldo's flame, Russian model Irina Shayk. Click through to see the hot cover and the rest of the beauties outside the NYC studios. Then visit Pop for more hot shots from Irina's shoot.