Coughing up someone else's phlegm
You think you've got AIDS
You're probably Australian. EDIT: I mean venomous, not poisonous. I am sorry
Yes, thanks, but I'm still a little horse."
Meowcus
Knowing that the first couple of times you cough that the phlegm isn't yours.
The first couple of times you cough, the loogeys aren't yours!