LUB
Standing for "Laughing Uncontrollably, Bro", it is used to replace clichéd abbreviations such as LOL and LMAO and so on. It is only to be used when actually laughing in hysterics in response to an online post, conversation etc.
Gary: "Look at this, dude! *sends link*"
Tom: "No way?! That's hilarious! LUB!"