a kush face is either when your really really stoned and its easy to tell when your high or you go to your dealers place for some new product & as soon as you smell it you make a face like a kid just woke up for christmas or when you're in the process of getting high you take a real big hit & right before you blow it out..... thats a kush face
When you are so high off that kush you can see it on your face.
"Damn nigga, do I look faded?"
" Yeah, your sporting your kush face."
Mom: "Why are you comin' in my house with that kush face!"