Q: Why do affairs happen?
A: “Affairs don't only happen for sex. Some reasons people get trapped in an affair:
if your spouse has a different kind of “lover” outside of your marriage, such as a consuming career or hobby.
or she did that hurt you rather than offering forgiveness and dealing with the root issue.
friendships with members of the opposite sex, take extra care in those relationships.
Your spouse doesn't live up to your expectations anymore.
Remember that you know your spouse's good and bad qualities, while you may only see someone else's good side because you don't know him or her well enough to see warts yet. That's known as “romanticizing” a relationship.”
Q: What are factors that can lead to an affair?
A: “The following are factors that can lead to marital unfaithfulness:
liaisons to build up their self-image or sexual self-esteem. Women are suspect to affairs to satisfy their longing for love, appreciation and tenderness. Beware of leaning on others beyond your marriage as primary sources for love, value and respect.
bills and household chores, you may be sliding into trouble. Holding in your thoughts and feelings does not enhance transparency in your relationship. Practice the art of small talk that can open the door to deeper sharing.
important not to build walls between you and your spouse. Some people mask their hurt while others spew their emotions. Neither method is constructive. Both ways create relational roadblocks. Unresolved conflict leads to isolation and leaves you vulnerable to fleeing your marriage.
enjoyed a date or a weekend getaway together. As the old adage says, "Couples that play together, stay together." If career, family and homes responsibilities are crowding out laughter and friendship with your spouse, you need to book in some recreational retreats with each other.
differing interests and hobbies are common issues that can keep couples apart. The more time you spend away from your spouse, the greater temptation to drift in your relationship.
raising children are two common reasons husbands and wives feel ho-hum in their relational intimacy. Romance, in an instant, can remind you of the reasons you love each other. All marriages require times of refreshing and an in-depth look at intimacy saboteurs.
any marriage. Beware of shaking things up in your sex life by dumping your spouse for another more promising lover. If you or your partner suddenly is disinterested in sex with each other, be sure to explore the true reasons.
marriage. Many couples succumb to affairs out of fading interest in their spouses. One way to continue your wedded bliss is to surprise your mate with love notes or an occasional unexpected outing or gift.
widen the gap between you and your spouse. Many extramarital affairs start when a frustrated spouse searches for a reality check in marriage by turning to an officemate or friend of the opposite sex for support. Dare to face the truth of your marital struggles.
why they fell in love. In our easy-come-easy-go culture, it takes courage and determination to honor commitment instead of convenience.
innocent husband or wife can fall prey to sexual temptations. Before you or your mate find yourself in compromising situations, talk about safeguards for your marriage. You may need to avoid after-work soirees, certain hotels on business trips and sexually compromising magazines, movies or television shows. Thinking "Just this once," can lead to a lifetime of regret.” 
Q: What are the hurdles to reconciliation?
A: “Awareness and understanding of the challenges that lie ahead can be your first step toward recovery.
Hurdle #1: Wrong Thinking
Many people mistakenly think that adultery is simply a wrong action, but it is also a violation of God’s divine order for marriage. A person who has had an affair must seek his spouse's forgiveness, not just for the adulterous act, but also for violating the marriage covenant, or sacred commitment. An intact marriage covenant creates an atmosphere of security and trust. That security and trust is what Kim needs in order to give herself freely to Jim. Only a restored sense of security and trust, borne of Jim asking and receiving forgiveness for breaking the covenant, can begin to restore Kim's confidence, peace and joy.
Hurdle #2: A Multi-Faceted Struggle
It is important to realize that a wounded spouse, such as Kim, will struggle with multiple issues. On one hand, her own sexual identity has become confused. Because of Jim’s act of immorality Kim finds herself asking deep in her soul, What is wrong with me that he would want someone else? There is also the issue of shame emerging in her spirit: shame that he would want any other woman, and especially that it was her friend Bonnie. How could it be Bonnie? Bonnie of all people! Another facet of Kim's struggle is her confusion over her lack of peace. Although she has forgiven Jim's acts, she needs to process and eventually forgive him for the ways she has been affected by his violation of their marriage vows.
Hurdle #3: Getting to the Real Problem
On the surface, it may appear that one's behavior is the problem, and that a promise "to change" is the solution. However, the real problem with someone like Jim is the fact that in his mind, he granted himself permission to break his marriage vows. To address only his behavior and overlook this issue of permission will leave both Kim and Jim in limbo. Without getting to the real problem, both spouses are destined to continue feeling as though something is wrong, but neither will understand what. They will limp along, wondering why their relationship is so tentative and distant.
Hurdle #4: Inability to Trust or Be Trusted
This ties in closely with Hurdle #1. Once a marital covenant has been breached, trust will be difficult — but necessary — to restore. Without trust, a couple cannot know intimacy. To set the stage for restored trust, Jim must be able to humbly admit that he is unable to manage his sin or keep his promises, and that he is deeply addicted to the pleasure of sin. At that point, he will be in a position to receive God's freeing grace and empowerment to choose differently. By being humble and openly dependent on God, Jim will also be putting himself in a position where Kim can begin to trust him again. As renewed trust grows between them, the couple will be able to enjoy rich intimacy, true fulfillment and sustaining joy.
By conquering these hurdles together, hurting spouses can overcome the damage of infidelity. By learning to trust God in a new, much deeper way, they can enjoy a stronger, more fulfilling marriage.” 
Q: When do I forgive them?
A: Don’t wait until you feel like forgiving. One of the harder parts of forgiveness is that we don’t always feel like forgiving. The problem is that feelings are often misleading and erratic. I learned a long time ago that you rarely feel your way into positive actions, but you can act your way into better feelings. You may not really want to wake up at five for that morning run, but you do it anyway. Afterward, you are so glad you made the extra effort because you feel good and have more energy. There is great satisfaction in making a choice to do something that your flesh was yelling at you not to do! You acted your way into a feeling.”
Q: What are some tips on how to deal with infidelity?
A: To help you recover, be prepared to:
afraid rowing isn't going to help you sort things out
were problems in your relationship or marriage before the affair
what went wrong; challenge your behaviour, wronged or not
at least some of that provides a basis on which to try to resolve the calamity
minutes or so a day, maybe longer - but most importantly it has to be a negotiated time
probably do now. It will get easier as you begin to deal with and sort out your relationship problems.
Q: How should affairs end?
A: There are three parts to the way affairs should end. The first part is revealing the affair to one's spouse, the second part is never seeing or communicating with the lover again, and the third part is getting through the symptoms of withdrawal after a permanent separation takes place.
Psalm 34:15-18 The eyes of the Lord are on the righteous, And His ears are open to their cry. The face of the Lord is against those who do evil, To cut off the remembrance of them from the earth. The righteous cry out, and the Lord hears, And delivers them out of all their troubles. The Lord is near to those who have a broken heart, And saves such as have a contrite spirit.
Psalm 103:12 As far as the east is from the west, So far has He removed our transgressions from us.
1 John 1:9 If we confess our sins, He is faithful and just to forgive us our sins and to cleanse us from all unrighteousness.
1 Peter 1:6-9 In this you greatly rejoice, though now for a little while, if need be, you have been grieved by various trials, that the genuineness of your faith, being much more precious than gold that perishes, though it is tested by fire, may be found to praise, honor, and glory at the revelation of Jesus Christ, whom having not seen you love. Though now you do not see Him, yet believing, you rejoice with joy inexpressible and full of glory, receiving the end of your faith—the salvation of your souls.
Proverbs 3:5-6 Trust in the Lord with all your heart, And lean not on your own understanding; In all your ways acknowledge Him, And He shall direct your paths.
Psalm 34:17-18 The righteous cry out, and the Lord hears, And delivers them out of all their troubles. The Lord is near to those who have a broken heart, And saves such as have a contrite spirit.
Psalm 18:6 In my distress I called upon the Lord, And cried out to my God; He heard my voice from His temple, And my cry came before Him, even to His ears.