jacking off in a corner
When someone leaves for no reason and everyone just assumes they’re getting their rocks off in a corner, because they’re too lazy to even pretend they’re doing something important.
He said he had to go. We all know he was hiding in the hallway.
She left the meeting like she was running from the police. We all know she was taking a break.
He vanished mid-conversation. We all know he was getting his head straight.