Acronym similar to "brb" (be right back), but with emphasis on a bodily function performed during such hiatus. BRBGP standing for "Be Right Back, Gotta Poop"
An example of bragplaining: It rained on the way to my modeling shoot. My designer dress got ruined! At least everyone said they were speechless at my beauty anyway.
When people want you to know how great they are but still whine at you, they may bragplain.
1. Ashley's Facebook statuses are so obnoxious. All she does is bragplain.