'Married At First Sight' Lawsuit -- Till Theft Of My Idea Do Us Part

A&E doesn’t think the idea of a marriage reality game show is sacred … at least that's the allegation in a new lawsuit.

Yaina Williams says she's the mastermind behind “Married at First Sight” -- a show that follows six couples that get hitched the moment they meet.

Williams claims she uploaded her treatment to a site called the TV Writers Vault back in 2011 and later found out an exec at Lifetime -- owned by A&E Networks -- downloaded it a year later.

She says the next thing she knew ... promos for MAFS were running on the network and she flipped out.

Williams says the the show is so similar to her treatment ... they even share the same tagline, "Can Love Happen at First Sight." And she says the use of experts, online voting and a 6-month couples check-up were all copied.

She wants a judge to order the network to stop airing the show. And she also wants money.

Calls to A&E have not been returned.