Men are visual creatures, and are therefore more prone to infidelity. Pastor John Piper, founder of Desiring God, said that even married men cannot escape lust for other women.

In a video message posted on his website, Piper said most men aren't proud of their lust for other women. There are two main reasons why they will try to hide this fact from their wives. First, it's because they like it, and next, their wives might respond in a way that would show their own insecurities.

Piper warned that men should deal with their hidden lust early on instead of keeping it a secret. Otherwise, Satan will pounce on their marriage and destroy it, he warned.

"There are a lot of people who don't even believe in Satan," he said. "And there are Christians who never give serious thought to how deceptive and destructive his designs are."

The theologian said Satan is quite deceptive, so his attacks often come when people least expect them. "You turn the light on, it goes away. You keep the light off, he might run right up your leg," said Piper.

Husbands might be terrified to confess their sins to their wives out of fear that they might not be forgiven. Piper quoted James 5:16 to encourage them: "Confess your sins to one another... that you may be healed."

If men let their hidden lust remain, Piper said they will allow darkness to remain and run rampant in their marriage. At the same time, they will be giving Satan the upper hand.

"Don't let yourself off the hook if you say, 'Well, I don't fantasise about doing things with other women. I just fantasise about seeing things,'" he said.

Piper paraphrased Jesus Christ in Matthew 5:28 when He said that anyone who looks at a woman to desire her has already committed adultery in his heart. "So, the question is," Piper said, "is that woman in your head your wife?"