When your wife is a whore that can't make it through your military tour without getting dick, so she ends up obtaining a boyfriend to fill in her dickspace despite her marital vows.
by Cuntrybarb787 October 25, 2019
Get the Boyfriend-in-lawmug. When you are talking to somebody about your sister in law's boyfriend and not wanting to include him as part of the family.
by I-HATE-MINE October 20, 2010
Get the Boyfriend-in-lawmug. You're (biological or unbiological) sister's boyfriend.
by MeghanMurder May 17, 2010
Get the Boyfriend-In-Lawmug. How you are introduced to people at a party by your girlfriends sister, when the parties in question are over 21 years old and very committed to each other.
Hey Sally, this is my Boyfriend-In-Law,(name), and hopefully soon he will make my sister an honest woman.
by Supertcher June 15, 2009
Get the Boyfriend-In-Lawmug.