Why people cheat? 😢

Hello

I am at a loss of where to head for insight so I figured a whole lot of strangers would be a great start.

I am 26 years old and I have a 23 year old sister. She is my only sibling and before Monday I would have said she was my closest most trusted friend.

On Sunday I received several messages from my brother in law -they’ve been married for 14 months- telling me how she has been having an affair for the past two months.

I am at a complete loss. I had noticed subtle changes in her personality but I never suspected her of something like this. Finding out that she has been lying to everyone with little regard to her husband, children and family is heartbreaking.

I am so affected by it because growing up we knew of the many affairs our father had and it destroyed our innocence in so many ways. We always had each other to lean on when our dad was found out, we went through it together! That is why I can not comprehend why a child of such marriage could grow up and put her OWN children through the same thing.

I understand that sometimes feeling change, and maybe she doesn’t love her husband anymore. What I don’t understand is the way she went about finding a new relationship. I feel partially guilty in a weird sense because as her older sister I always tried to make life as easy as possible for her. Both me and my parents rarely held her accountable for her mistakes or shortcomings.

I fear that this has change our relationship forever and it saddens me. I cannot understand her situation and it’s why I am here -writing this looooong post. If you’re still reading I would love some input. Whether it’s from a sister, a cheater, or a friend. I have ran through every possibility in my mind and I just don’t know where to start.

I know many might think I’m too invested in her relationship and I’m trying to put the correct distance there but it doesn’t change the hurt. I would love to be able to understand her position in hopes of healing our relationship. However she has completely shut down and I am still to upset over it all that I fear speaking with her right now might cause more harm.

Thanks for reading! Let me know your thoughts.