Earlier this year, my husband and I lost our unborn child. That loss, combined with an already troubled marriage and randomly running into my ex after seven years, equaled the perfect storm. I emotionally and mentally cheated on my spouse with my ex. My husband and I are reconciled now, and we continue to work on our marriage. My question is: Do I need to offer an apology to my non-Christian in-laws?
I am very sorry for your loss, and grateful to hear that you and your husband are working on your marriage. I pray you and he will be able to heal.
As for your in-laws, do they know the details of why you and your husband were temporarily separated? Did they indicate to you that they expect an apology? If not, then I don’t think you are obliged to involve them in the intimate details of your marriage. If they do know the circumstances, or seem to expect an apology, then by all means apologize. Not because you must, but because it will serve as an act of good faith in mending relationships with your husband’s family. I don’t think you specifically have to refer to what you did though. It should suffice to say simply, “I am very sorry for my actions, which contributed to the breakdown of my marriage, and which hurt you very much. I hope you will be able to forgive me.”