Nibling-in-law (only spouse's nibling).
My nibling-by-marriage is a good person.
by QWP998756 October 15, 2021
Get the nibling-by-marriagemug. 
Get the nibling-by-marriagemug. Spouse's nibling's spouse.
My nibling-by-marriage-in-law is a good person.
by NSBC968755 February 25, 2023
Get the nibling-by-marriage-in-lawmug.