Exactly

Millions of couples today stay together primarily for economic reasons. The state incentives this even for poor or middle class couples through the special tax breaks or welfare state benefits allowed to married couples and their offspring which they do not give to unmarried or common law arrangements. You can say you personally would never do it, but the reality is many are doing it. It is almost the underlying principle of mail order brides too, a business that is booming in the internet era too. (Sadly, they're all too old for me).

Markie should really read Engels.