A fork of Rural Dictionary
1- Stepsibling's husband.
2- Spouse's stepbrother.
My stepbrother-in-law is a good person.
The title given to someones brother of sisters boyfriend if they're not married
Juan: Who's this Harry geezer?
Tom: Oh he's my sisters boyfriend, that makes him my stepbrother-in-law
Juan: Surely he's your stepbrother?
Tom: Nah fam, he's not married to my sister
1- Stepsibling's husband.
2- Spouse's stepbrother.
stepbrother-in-law.