It's fathers-in-law.
Sons-in-law is plural.
The plural is "sisters-in-law."
Fathers-in-law is the plural of father-in-law
The plural of mother-in-law is mothers-in-law.
Fathers-in-law is the plural of father-in-law
The plural form of law is laws.
what is the plural form of daughter in law?
Sons-in-law is the plural for son-in-law.
The plural of daughter-in-law is daughters-in-law.
The plural form of the noun mother-in-law is mothers-in-law.
The plural is mothers-in-law. (not mother-in-laws)
The plural of bye-law is bye-laws.