1. It is used for laughing when you really aren't laughing, but you want to give the allusion that you are laughing.
Mo - What's the difference between chopped beef and pea soup?
Everyone can chop beef, but not everyone can pea soup!
Shawn - LBNRL!
Mo - what is LBNRL??
Shawn - tehehehehe
Laughing but not really but I still think it's funny I'm just not laughing. Used in conversations over the internet instead of "lol" when you do not actually laugh out loud.