Don't write back.
A post-script abbreviation used to indicate that a message does not require a reply on behalf of the recipient.
Often used as a form of reverse-psychology to instigate said reply.
1. Malfoy: Hey dude, it's Foy. I realised that I'm gay. dwb.
2. Dad: I'll be home at 6. dwb.
3. Nervous dude: I love you. dwb.
