When dating, a lot of us fall into the trap of thinking that chemistry and attraction is love. While those components are necessary to want to keep someone around, those things can also trap you into staying in bad relationships.
These superficial aspects are usually only temporary and like all things in life, familiarity breeds contempt at the worst. At best, we start taking those things for granted.
I’ve heard more than too many times that “the heart wants what it wants.” People often use this as an excuse to do stupid shit with stupid people and end up getting burned as a result. Usually the “heart” translates to lustful desires and people who feel entitled to chase their “hearts” towards happiness end up either cheating or feeling discontent in their marriage or LTR.
In the end, integrity and self control are probably the best way. At least if raising a healthy family is the goal. You have to be willing to kill your ego, there is a huge risk though if your partner isn’t.