It was over dinner when it dawned on Matt that he might be having a threesome that night. He and his partner were out at a restaurant with her friend, another bisexual woman.
https://www.theguardian.com/lifeandstyle/2020/feb/11/threesomes-men-women-sex-psychology
origin - https://www.pipiscrew.com/2020/02/the-psychology-of-the-threesome-everyone-wants-one-but-whos-truly-ready/ the-psychology-of-the-threesome-everyone-wants-one-but-whos-truly-ready