"Machetunim."

Yiddish mekhutn 'father of one's son- or daughter-in-law'; mekhutonim 'in-laws'; mekhuteneste 'mother of one's son- or daughter-in-law'; mekhutoneshaft 'relation by marriage'. Bonus saying: vos far a mekhutn bin ikh dir? "What am I to you?" The words are from the Hebrew MChTN 'relative by marriage' < ChTN 'to become related by marriage', related to ChTN 'daughter's husband', cf. Arabic chatar 'son-in-law, bridegroom'.

Ceci n'est pas un seing.