Person B: That's not awkward, that's sad and soul crushing.
As you can see, Person B is well read and has a firm grasp on the definition of the word awkward and that awkward moment when, Person A on the other hand is a sad plebeian who hasn't come to such realizations.
The phrase can also be used to send a message to someone.
2. That awkward moment when you ex girlfriend relizes you had been cheating on her when you were going out.