Vomiting Stickers

"I have a smiley face sticker on my test." 
"Good for you." 

"And you?" 
 "None of your business!"

 "You have one with a frowny face right?" 
"No, I don't have one." 

"I didn't even know they made stickers with vomiting faces."

Notes:
asunto can be used formally for business, or matter, but can also be used to tell someone to mind their own business.
ninguna is feminine because it refers to the feminine antecedent pegatina.  The borrowed English term sticker is also used in some countries.