Not to thread jack, but there are alternatives to conventional marriage and monogamy IF BOTH partners are fully desiring opening their relationship to include others in a safe, ethical way. It's a minefield of hurt if it isn't an equally desired solution. The relationship has to be strong and mature to begin with, and jealousy-free. This scenario sure wouldn't fix a dysfunctional one.
I wouldn't enter into a marriage and monogamy if I didn't think I could manage to stick to it. Better to be with partners who feel the same way and aren't chafing in the harness, so to speak. Monogamy is not for everyone.