Talking to people at school that you only know because they sit there another time during the day.
Writing a question on a desk and having someone else answer it is considered desk chat.
Meeting the person in real life and using desk chat is a less common way to do it, but is still used sometimes.
Person 1: "Hey man, some girl just gave me her number through desk chat"
Person 2: "Seriously? have you even met her?"
Person 1: "Nope"
6👍 6👎