when your a messy eater and leave food around your mouth.
*jordan has a crumb on his top lip*
phil: oi jordan's done a stacky
tyler: yeah i know, how embarrasing
When a male's ball sac is sweaty it becomes sticky. Instead of saying "I have a sticky sac" he can simply say "I have a STACKY".
Hey dude, I have such a stacky after working out earlier.
I wouldn't give my boyfriend head, because he had such a stacky!