An empty threat made in response to perceived asshole-ery, typically via text message.
If you are an asshole then maybe we won't hang out Sunday.
Apart from the original Richard Keys usage of the phrase, to hang out the back of something can be used as an expression of approval of something well done.
(after eating a good meal cooked by a friend) "that pasta was great, you really hang out the back of it"
Having sex in the electric vehicle while waiting for it to charge.
Needed to return the EV rental with more than 70% charge, so we ended up hanging out at the supercharger.
Me and my girl were hanging out in the blankets
november 24 is national hang out with the plug day
Yo it’s National Hang Out With The Plug Day let’s hit tony see if he wants to run up monopoly.
When two friends overly defend each other.
Similar to bumlicking except it comes from both sides not one
‘Lewis and Mitchell are always hanging out the back of each other!’
‘Literally! They always defend each other so fast it’s like they’re secretly partners!’