I'm taking my kids to spend time with my out-laws because I feel like they should be able to know their grandparents, aunties, uncles and cousins on that side of the family, regardless of how my ex feels about me.
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.
Doug: Since we live in a state that doesn't recognize gay marriage, I'm not sure what to call your mother. She's not an 'in-law'...
Ed: Call her your mother-out-law. I'm sure she'll like that.
Noun: the Mother of one's ex-husband or ex-wife. Formerly known as Mother-In-Law.
Abbreviated: MOL
Term of endearment: when you kept your ex's Mom in the divorce.
Derogatory: when your ex can't be bothered so they send their Mom.