Mockturnal

When you say you’re going to stay up at night and then fall asleep

Man: “You said you would stay up and play games man” Joe: “I know but I’m really tired” Man: “Nah you’re mockturnal”

mockturnal

The act of staying up all night (usually drug induced) and telling others that you were sleeping.

"Bart said he slept last night, but I think he was mockturnal."