I stepped up and said hi... Gaga and Sully recognized me as well, because I had met them not too long before during a couple of meet & greets. 
It was funny to see how Gaga and her small entourage went about their business without people noticing Gaga all too much. Some folks kinda looked at her for a second, maybe because of her appaerance (white vest, short black pants, high heels, and very white short blond hair). But nobody stepped up to her or bothered her at all. Not too many Gaga fans at the airport...
