headphone bluffing

Wearing a pair of headphones, typically within the context of a group of people studying, without actually playing music. The benefit of headphone bluffing is that people typically won't talk to you but you can still hear everything that is going on, therefore allowing you to be passively engaged in conversations of your choosing.

"Yo, I want to talk to Lucas but his headphones are in!"
"Look out, he might be headphone bluffing! You listening in, Luke?"