21 For it is from within, out of a person’s heart, that evil thoughts come—sexual immorality, theft, murder, 22 adultery, greed, malice, deceit, lewdness, envy, slander, arrogance and folly. 23 All these evils come from inside and defile a person.

-Mark 7:21-23, NIV

An idea was planted. The Cheater watered it, and it produced the rotten fruit that spoiled the marriage. Cheating, in other words, was the overflow of the Cheater’s heart.

This is why it is “fruitless” to focus on the marriage relationship or the faithful spouse’s performance as a spouse. Neither caused the adulterous behavior. It was an “inside job”–i.e. inside the Cheater.

Some Cheaters might even have created a decision tree or mind-map about what to do with their relationship. If any of those options included an affair, you know sin was already deeply rooted in their heart.

It was already an emotional affair as they had already consummated the relationship in their hearts.

Cheaters contemplating cheating are simply ticking bombs. They will eventually explode their marriage when the wickedness in their hearts finally overflows…

…and that overflow’s source is purely the Cheater’s fault as it is coming from their own heart!