famenemy 

Famenemy, pl. famenemies: A family member who is also your enemy.

This can be blood relatives, related by marriage or just considered family. Mother/Father, Sister/Brother, Husband/Wife, boyfriend/girlfriend, Aunt/uncle, real cousin/play cousin etc. {frienemy}

My famenemy sister used our family trust and sympathy to set me up for a financial loss.

famenemy by CCedar September 1, 2019

Fam-enemy 

A person or persons who pretend to be your family.

My fam-enemy has a massive ego.

Fam-enemy by Ladybug Mafia Queen March 28, 2025