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The sister of my girlfriend/boyfriend. For when you're not in a lawful/legal relationship with someone, but still have a close relationship with their relatives. Relative-In-law is a legal relationship. Relative-Out-law is a relationship with no legal standing.
Man, my sister-out-law is hella cute.
by Willuknight October 31, 2017
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Apr 21 Word of the Day
I've been jabbed
by Francesco II March 20, 2021
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