Dirty lala is when you get some of your own poo in your hand and run up behind someone and rub it accross their eyes and then yelling "you got pink eye!"
I saw a guy I knew from high school, he was a real jerk, so I crapped in my hand and ran up behind him and smeared the poo accross his face and yelled you got pink eye! he got a dirty lala
dirty lala - when you stick your finger in (your) butt hole and then rub it in someones eye to give them pink eye
keith is a dumbass, so I gave him a dirty lala, now he has pink eye