VIDDY THIS: Hey, kids! Let's talk video adds. This week MTV welcomes Fall Out Boy, "My Songs Know What You Did in the Dark (Light Em Up)," Lil Wayne f/Drake & Future, "Love Me" and Rihanna f/Mikky Ekko, "Stay." The latter clip, boosted by the pair's Grammy-show perf, also bowed at VH1, as did One Republic, "If I Love Myself." Speaking of which, we're celebrating Valentine's Day with a brand-new romance. Which is what we call using the other hand. (2/13p)