Affairs/Infidelity is defined as sex outside the marriage/the primary relationship when it is against the couple's definition of the contract.
Affairs and betrayals can bring any relationship to breaking point. Once the bond of trust is shattered, it unleashes an intense tide of emotions in the person that has been betrayed.
There are numerous reasons for people to betray someone’s trust or commit an act of infidelity. It depends on the circumstances and needs of the people involved. In general, the reasons can be divided into two main groups - to save the relationship or to end it.