, ▁but ▁sometimes ▁father ▁and ▁son ▁have ▁a ▁common ▁wife , ▁which ▁is ▁a ▁unique ▁family ▁structure ▁in ▁the ▁world . ▁Other ▁forms ▁of ▁marriage ▁are ▁also ▁present , ▁like ▁group ▁marriage ▁and ▁mon og am ous ▁marriage . ▁Poly and ry ▁( es pecially ▁frat ernal ▁poly and ry ) ▁is ▁also ▁common ▁among ▁Buddh ists ▁in ▁Bh ut an , ▁Lad akh , ▁and ▁other ▁parts ▁of ▁the ▁Indian ▁sub cont inent . ▁ ▁C elt ic ▁trad itions ▁Some ▁pre - Christ ian ▁C elt ic ▁pag ans ▁were ▁known ▁to ▁practice ▁pol yg amy , ▁although ▁the ▁C elt ic ▁pe op les ▁wa ver ed ▁between ▁it , ▁mon og amy ▁and ▁poly and ry ▁depending ▁on ▁the ▁time ▁period ▁and ▁area . ▁In ▁some ▁areas ▁this ▁continued ▁even ▁after ▁Christian ization ▁began , ▁for ▁instance ▁the ▁Bre hon ▁La ws ▁of ▁G ael ic ▁Ireland ▁explicitly ▁allowed ▁for ▁pol yg amy , ▁especially ▁amongst ▁the ▁noble ▁class . ▁Some ▁modern ▁C elt ic ▁pag an ▁relig ions ▁accept ▁the ▁practice ▁of ▁pol yg amy ▁to ▁varying ▁degrees , ▁though ▁how ▁w ides p read ▁the ▁practice ▁is ▁within ▁these ▁relig ions ▁is ▁unknown . ▁ ▁Christian ity ▁ ▁Pol yg amy ▁is ▁not ▁forb idden ▁in ▁the ▁Old ▁Testament . ▁Although ▁the ▁New ▁Testament ▁is ▁largely ▁silent ▁on ▁pol yg amy , ▁some ▁point ▁to ▁Jesus ' s ▁repet ition ▁of ▁the ▁earlier ▁script ures , ▁not ing ▁that ▁a ▁man ▁and ▁a ▁wife ▁" sh all