Dear [Name],

I am writing this letter to express my sincerest apologies for my infidelity. I know that I have hurt you deeply and that no words can fully express the sorrow I feel for my actions.

I realize now that I was wrong to betray your trust and that my actions were inexcusable. I know that I have broken our relationship and that I have caused you deep pain and suffering.

I am deeply ashamed of my behavior and I regret it deeply. I know that no amount of words can make up for what I have done, but I want you to know that I am truly sorry.

I understand that I have hurt you and that it will take time for you to forgive me. I want you to know that I am committed to rebuilding our relationship and that I am willing to do whatever it takes to make things right.

I am committed to being honest and open with you in the future and I will do my best to rebuild your trust. I understand that it will take time, but I am willing to do whatever it takes to make things right.

I am truly sorry for my actions and I hope that one day you can forgive me. I know that I have hurt you deeply, but I hope that you can find it in your heart to forgive me.

Sincerely,

[Your Name]

Dear [Name],

I am writing to you to express my sincere apology for my unfaithfulness. I know that I have hurt you deeply and that you are probably feeling a lot of pain and anger right now. I am so sorry for what I have done and for the pain that I have caused you.

I know that no amount of words can make up for what I have done, but I hope that you can find it in your heart to forgive me. I realize that I have made a mistake and I am willing to do whatever it takes to make it right.

I understand that trust is an important part of any relationship. I have broken that trust and I know that it will take time to rebuild it. I am willing to put in the effort to do whatever it takes to regain your trust. I want to prove to you that I am committed to this relationship and that I am willing to do whatever it takes to make it work.

I know that I have hurt you deeply and that it will take time for you to heal. I want you to know that I am here for you and that I am willing to do whatever it takes to make things right. I am willing to talk through our issues and to find a way to move forward.

I am so sorry for what I have done and I hope that you can find it in your heart to forgive me. I know that I have made a mistake and I am willing to do whatever it takes to make it right.

Sincerely,

[Your Name]

Dear {Recipient},

I can't count the number of times I started this letter, only to delete everything I've written. Sometimes, there are no words to adequately express the guilt and regret one feels about something they did, especially when they've hurt someone who loved and trusted them so deeply.
I know “sorry” is not enough for what I did, but I'm really sorry for all the pain I put you through. I was extremely selfish and risked everyone's happiness. Being unfaithful is unforgivable, and I deserve all the anger that you feel towards me.

It pains me to see you hurting and I want nothing more than to regain your trust and rebuild our {relationship/marriage}. You probably want some time alone though, so I will give you the space you need to heal. Where we go from here is up to you. I will accept whatever decision you make, but I'm still hopeful that you'll allow me to repair the damage I've done.

Again, I'm deeply sorry for the hurt I've caused. Please take good care of yourself.

Thinking of you,

{Your Name}

Dear {Recipient},

Where do I begin? I messed up real bad—{number of} years with the most amazing {man/woman} I've met, and I threw it away like it was nothing. How stupid can I be?

You've been nothing but kind, caring, generous, supportive—everything that I could ask for in a partner and more. You didn't deserve any of this. What I did was wrong and unacceptable, which is why I've already ended things with the other person. Whether you take me back or not, it really is over between {him/her} and II'm very sorry for putting you through all this.

You might not believe me, but I still love you and I hope that you'll give me another chance. What's done cannot be undone, but I promise to make it up to you and I'll prove that I'm worth staying with. I'm really, really sorry.

With love and regret,

{Your Name}

Dear [Name],

I am writing to apologize for the unhappiness I have caused you due to my unfaithfulness. I know that my actions have caused you a great deal of pain and I regret that more than anything. I feel deeply regretful and ashamed of myself for my actions and I understand that no apology can undo the pain and hurt I have caused you.

I realize that nothing I can say or do will make up for my mistake, but I want to assure you that I am taking steps to ensure that I never make this mistake again. I am taking the time to reflect on my actions and learn from my mistakes. I am also taking the time to work on myself and become a better person.

I have been reflecting on my actions and I understand that my behavior was wrong. I have been struggling with a lot of things lately and I should have handled them differently. I should have been honest with you and I should have talked to you about my feelings instead of turning to someone else.

I am truly sorry. I want to make things right and I am willing to do whatever it takes to make it up to you. I want to rebuild the trust and faith I have broken and I want to be a better partner to you. I know it will take time and I am willing to do whatever it takes to make it up to you.

I understand that it will take time for you to forgive me and I am willing to do whatever it takes to earn your trust back. I am committed to rebuilding our relationship and I am willing to put in the effort to make it work.

I know I cannot undo the hurt I have caused you, but I hope that you can find it in your heart to forgive me and give me another chance. I love you and I want to make things right.

Sincerely,

[Your Name]

Dear [Name],

I am writing to apologize for my unfaithful act. I know that my behavior was wrong and that it has caused you pain and hurt. I am truly sorry for what I have done and I want you to know that I regret my actions.

I understand that my actions have broken your trust and that it will take time for you to forgive me. I am willing to do whatever it takes to make it up to you and to prove to you that I am truly sorry. I am willing to take the time to listen to you and to understand how my actions have affected you. I am also willing to take responsibility for my actions and to make amends in any way that I can.

I know that I have hurt you deeply and that I cannot undo the damage that I have done. I want you to know that I am committed to rebuilding our relationship and I am willing to do whatever it takes to make things right. I am willing to work with you to come up with a plan to move forward and to rebuild the trust that I have broken.

I am deeply sorry for my unfaithful act and I hope that you can find it in your heart to forgive me. I know that it will take time, but I am committed to doing whatever it takes to make it up to you. I am truly sorry and I hope that you can find it in your heart to forgive me.

Sincerely,

[Your Name]

Dear [Friend],

I am writing this letter to apologize for the unjustified betrayal I have caused you. I know that my actions have caused you pain and I am truly sorry.

I realize that I have been selfish and inconsiderate in my actions and I take full responsibility for them. I should have thought about the consequences of my actions and how they would affect you. I should have been more mindful of our friendship and the trust that you had in me.

I understand that my betrayal has caused you to doubt me and our friendship. I want you to know that I am deeply sorry and I regret my actions. I want to make it up to you and prove that I am a trustworthy friend.

I am willing to do whatever it takes to make it up to you. I am willing to talk openly and honestly about the situation, and I am willing to take any steps necessary to rebuild our friendship.

I understand that it will take time for you to forgive me, and I am willing to wait. I hope that you can find it in your heart to forgive me for my betrayal. I promise that I will never do anything like this again.

Once again, I am deeply sorry for my actions and I hope that you can forgive me.

Sincerely,

[Your Name]