Polyandry

Polyandry is a relationship in which a woman has a relationship or marriage with multiple/many men. This could be due to religious beliefs or cultural acts, but it is not required.

See also: Polygyny

Flag
The polyandry flag was coined by Deviantart user NonMonoPrideFlags on December 3rd, 2015.

Resources
https://www.deviantart.com/nonmonoprideflags/art/Polyandry-Pride-Flag-576035693