Babygirl Bae

Typically after I search the web, or check for a "how to" video on youtube I have some sort of success in figuring things out that I couldn't, but this is something I have yet to figure out so figured I'd post here and ask if anyone can help me... I've seen the lip biting gesture but where it's actually animated and repeatedly loops/moves.... does anyone know how to get this or make this work? if so, i'd be so grateful... thank you! ^.~