“My ex-boyfriend cheated on me with my sister.
Unsurprisingly, I never got an apology from either one.”
Apparently, this atrocious act is more common than you’d think!

Here’s what people shared:
1.
“My husband cheated on me with my best friend of almost 10 years.
Our old housemate had moved out, which left our extra bedroom open.

My BFF moved in.
A couple months later, she up and disappears for days.
Then, she started acting super weird and kept avoiding me.

Come to find out via a friend that my husband had sex with her while I was at work.
It gets better, though!
They did it in our bed.

But wait, IT GETS EVEN BETTER.
He did it to get revenge on me for cheating on him years prior.
He admitted later that he did it intentionally to get back at me.”

“I had cheated years prior and regret it to this day because of the pain it caused.
He also effectively destroyed my closest friendship with his ‘payback.’
I lost my friend group by extension.

We did stay together, but against my better judgment.
samisunshine23
2.
“This is my friend’s story.

So, her ex-boyfriend cheated on her with her stepmom.
Her mom wasn’t really in her life because she and daddy dearest had gotten divorced.
My friend was over the moon to finally have a mom figure in her life.

Vivica and my friend did everything together; they were extremely close.
One day, my friend calls me in tears, and it’s for the sickest reason.
Her boyfriend at the time had broken up with her because he had been cheating with Vivica.

Eventually her dad found out, and he and Vivica got divorced.
queenlovie
3.
A week after we buried my uncle, my father left my mother for his sister-in-law.

Apparently, my father married his sister-in-law a few years after the divorce went through.
I have zero contact with my father after everything he put us through.”
Anonymous
4.
“I cheated on my husband with my stepsister’s husband (my brother-in-law).
My mom was married to my stepsister’s dad.
My marriage was over, but at the time, I wasn’t sad.
I continued to see the other person for a little bit after the fact, but eventually that stopped.
“He was my first boyfriend in high school.
I was young, naive, and completely in love with him.
He was my first everything.
After six months, I found out he was sleeping with my best friend.
“My ex-husband cheated with my best friend, who was a bridesmaid in our wedding.
They had a kid before I could even file for divorce.
It was a slap in the face.
kaylamoyer4
7.
How did I find out?
Cut to a year or so later, and my ex dumped me out of the blue.
liz_adams
9.
They had been exchanging flirty texts and seeing each other behind my back.
Unsurprisingly, I never got an apology from either one of them.
Apparently neither of them thought they did anything wrong.
My sister had the nerve to cry and be offended when I cut her out of my life.
I also considered a restraining order because she kept coming to my door.”
“Sadly, some relatives took her side, because ‘she has been going through some issues.’
This also was not the first time she did something like this.
She has a history of trying to date men who are in a relationship.
“When I was 18, I moved eight hours away, but my boyfriend and I stayed together.
Before moving, he and a friend of mine ended up becoming friends during a class they had together.
They had similar names and the same birthday, and my friend was telling me all about this.
I had my suspicions, but I left it alone because I trusted my boyfriend.
Fast forward a few months.
I moved away during the summer, and the relationship got rocky.
I had a gut feeling, and on New Years Eve, we FaceTimed for the ball drop.
My friend was in the background of the FaceTime and everything was denied.
They said they were just hanging out.
I called him immediately freaking out, and we broke up.”
They didnt last, and Im gay now.”
shyraanichole
11.
“I dated my ex for four years.
We went out with her almost every weekend.
He would have her over and sleep with her in our house that we bought together.
When I finally found out, of course he cried and cried and begged me to stay.
When I confronted her, she pretended she thought I knew about the relationship.
They are still together.
“One thing they were right about is that they are a much better fit.
Im doing great now and feel closer to myself than I ever have.
Shes a horrible person, but I still hope she makes it out before he inevitably discards her.
Thats going to be really embarrassing for her.”
“I had a best friend in San Diego who needed a place to stay.
My husband and I had transferred to San Francisco from San Diego.
When she called me to say she needed a place to stay, I said of course.
She moved in and they proceeded toresumetheir affair.
I found out when her ‘friend’ from her workplace called and clued me in.
You should’ve seen their faces when they came home to their bags packed.”
“I was in the Navy at the time and had been married for just over five years.
I was currently on shore duty, so no deployments or anything in the previous year or so.
We were planning a week-long road trip with my buddy, who was also my supervisor.
Just before the trip, we had a big argument, and she was all over my buddy.
It turned into a grade-A cluster, and we ended up separated by the end of the night.”
So, they went on the road trip while I stayed home and dealt with my anger.
End of the week, they get back.
Next Monday, we’re both back at work.
He’s still my supervisor, so we are dealing with that.
Our higher-ups were told what was going on and offered to transfer one of us, but we declined.
Now the fun stuff!
In California, at the time, there was basically a six-month period between filing and finalization.
We worked together that entire time and even attended functions at other friends' places, etc.
We kept it from becoming a huge conversation item.
I did house-sit for them while they went on a honeymoon.
She took the dog and I could watch the dog without any trouble, so I did that.
We were fortunate that we didn’t have kids, so there was no reason to ever speak again.
Haven’t talked to them since (that was in 1995).
Couldn’t even tell you where they live nowadays.
A good learning experience.”
I had only recently given birth to our child, and intimacy was a struggle.
“My mother and the love of my life/my first love/the guy I gave my virginity to.
We had gotten our phones at the same time, so it wasn’t an old message.
Then, I started dissecting and going through everything.
“Since that day over a year ago, I no longer talk to my mom.
I tell everyone she died, because to me, she did.
And, I’m still with that guy.
It’s been a bumpy road.
My self-esteem is gone, and because of that, I’ve gained so much weight.
I started drinking bad.
“This was in high school (15+ years ago), and I was talking to this guy.
My BFF at the time knew this guy too (small town).
She goes in and I wait in the car like an idiot.
Well, 30 minutes go by and I go home.
They were hooking up.
She went to prom with him (obviously I never talked to him again).
Mutual friends lied and told her he had herpes.”
headsup7up
17.
“Best friend and boyfriend.
I had suspicions, but they both gaslit the hell out of me.
“Both told me I needed therapy, but months later, he finally admitted they were sleeping together.
The whole situation gave me so much anxiety, I dropped out of school for five years.
People are trash.”
“I just found out my spouse cheated on me with their best friend.
They blamed the material of the shirt, but they wore an undershirt.
They would also tell me a certain colleague would ‘scratch’ their back.
But these scratch marks looked like scratch marks from sex.
I was 18 and naive.
This wasn’t the first incident.
I just found all of this out a few weeks ago, and my heart shattered.”
“My spouse promised me they would be my safe person, as I’d been cheated on before.
To find out that 25 years have been a lie is gut-wrenching.
We have children, and I honestly don’t even care anymore.
And yes, all these people they cheated with were our mutual friends.
My spouse and I no longer have any sort of relationship and we don’t talk to each other.
I no longer speak with these ‘friends.’
I ended up having to file a missing persons report and say my truck was stolen.
I finally found her in the next county with my little brother and some of his friends.
I questioned them and both said nothing was going on, but I had that gut feeling.
One night, I picked her up so we could talk.
“At about the same time, I heard him come in my back door.
That situation has put a big hurting on our family.
Of course it didn’t last long at all, and he’s sitting in jail right now.”
“A coworkers boyfriend cheated on her with another coworker.
Turns out all of those photos together were actually WHILE they were a couple.
She had been happily sharing their relationship all over social media and just wasn’t tagging him.
In the three years I had been with him, he had also been with her.
She got to meet the family, the friends, etc.
They even bought a HOUSE together.
Do the internet searches before falling in love.”
Note: Submissions have been edited for length and/or clarity.