Actually, maybe it is. At least one guy hopes so:
From the AP, via ABC News:
Nathan Collier and his wives Victoria and Christine applied at the Yellowstone County Courthouse in Billings on Tuesday in an attempt to legitimize their polygamous marriage. Montana, like all 50 states, outlaws bigamy — holding multiple marriage licenses — but Collier said he plans to sue if the application is denied.
“It’s about marriage equality,” Collier told The Associated Press Wednesday. “You can’t have this without polygamy.”
Welp, there you have it.
Buckle up, kids.