Photographer David Keeler has filed a lawsuit against Christina Aguilera and a bodyguard. The shutterbug alleges that after he snapped pics of the singer leaving a nightclub in May 2003, her protector told him he "needed to learn respect," socked him and spat on him. Aguilera's rep maintains that she witnessed no such incident and has no reason to believe that it even occurred. Of course, Triple-Xtina says the same thing about her stint as a wholesome Mouseketeer, too.