This stands for *Must Be Nice* a lot of people use this when they see other people in goofy or cute relationships.
by TheRealBeale 🤩 October 7, 2018
 Get the MBNmug.
Get the MBNmug. by Justin Glucose October 28, 2016
 Get the mbnmug.
Get the mbnmug. must be nice..........
by wikked January 6, 2005
 Get the mbnmug.
Get the mbnmug. 1. stands for "must be nice" and used sarcastically when someone tells you something that makes them sounds wealthy, carefree, or conceited.
Wealthy Chick: My parents, my sister and I are going to Aruba for Christmas for a week then to Argentina and Brazil to spend the New Year.  
Poorer Friend: MBN! shit!!!
Wealthy Chick: What does 'mbn" mean?
Poorer Friend: it means that it Must Be Nice, mutherfucka! Tell your parents to hook ME up!
Poorer Friend: MBN! shit!!!
Wealthy Chick: What does 'mbn" mean?
Poorer Friend: it means that it Must Be Nice, mutherfucka! Tell your parents to hook ME up!
by El Muñeco December 28, 2005
 Get the mbnmug.
Get the mbnmug. by QveenArii November 19, 2017
 Get the MBNmug.
Get the MBNmug. by bbg122567 December 9, 2018
 Get the Mbnmug.
Get the Mbnmug. 