@newhere,
NO, NO, NO.
She stays behind.
Some cultures allow, even endorse 'mistress's', usually only because she, (the wife), knows he couldn't afford a divorce, (she'd clean him out) and because the sex maniac is a disrespectful lout and she prefers her own bed anyway.
Please plan on the comfort of finding a new man that would never consider such a ludicrous idea. The honest, loving, considerate ones out there would absolutely never consider such a thing.
Go back to church, get involved, you'll find a man. Or many to choose from.