Words and the way you use them are terribly significant, but the surest way to establish trust in marriage is through your actions. Build a record of choices and deeds that proves to your partner you can be trusted at all times—especially in regards to your relations with the opposite sex.
For my own part, I can honestly say that I have never considered cheating on Shirley. The very thought of hurting her and inviting God's wrath are more than enough to keep me on the straight and narrow. Furthermore, I would never destroy the specialness that we have shared for all these years. But even in marriages that are based on that kind of commitment, Satan will try to undermine them.
He laid a trap for me during a time of particular vulnerability. Shirley and I had been married just a few years when we had a minor fuss. It was no big deal, but we both were pretty agitated at the time. I got in the car and drove around for about an hour to cool off. Then when I was on the way home, a very attractive girl drove up beside me in her car and smiled. She was obviously flirting with me. Then she slowed down, looked back, and turned onto a side street. I knew she was inviting me to follow her.
I didn't take the bait. I just went on home and made up with Shirley. But I thought later about how vicious Satan had been to take advantage of the momentary conflict between us. Scripture refers to the devil as "a roaring lion…seeking whom he may devour" (1 Peter 5:8, kjv). I can see how true that description really is. He knew his best opportunity to damage our marriage was during that hour or two when we were irritated with each other. That is typical of his strategy. He'll lay a trap for you, too, and it'll probably come at a time of vulnerability. Beautiful, enticing, forbidden fruit will be offered to you when your "hunger" is greatest. If you are foolish enough to reach for it, your fingers will sink into rotten mush on the back side. That's the way sin operates in our lives. It promises everything; it delivers nothing but disgust and heartache.
Someone said it this way: All you need to grow the finest crop of weeds is a tiny crack in your sidewalk.5 Essentials for Lifelong Intimacy
By Dr. James Dobson