Few things harm a relationship more than an affair. Whether the affair is emotional, a 'one night stand,' long term or a cyber-affair, the betrayal delivers a life altering blow. Will the injury to the relationship prove fatal?
In my experience as a relationship counselor there are some essential steps a couple must take for there to be any hope the relationship can survive an affair. If done wisely, there is hope the relationship will come through the ordeal stronger than before.
1) End the affair immediately. Kindly, completely, utterly. This has to come first if you are serious about reconciliation. 'Friendship' is not an option.
2) Re-commit to the relationship.
If either of you aren't sure about staying together then, for God's
sake, say so! Confusion is OK just don't let that be an excuse to avoid
talking about the reality.
3) Full disclosure. If your partner wants to know the details you owe them the details. Help them understand the reality because believe me, as bad as it is, it isn't as bad as what your partner is imagining. Sometimes they really don't want to know. Fine, let them tell you that directly. Don't assume it.