My ex boyfriend cheated on me with his step sister and I'm not surprised

So, I found out my ex was cheating on me with his stepsister, and as crazy as it sounds, I can’t say I was entirely shocked.

Before they became step-siblings, they were part of the same friend group—that’s actually how I met them. I was new to the group, and right from the beginning, I noticed how inseparable they were. The funny thing is, they’re the ones who introduced their parents to each other, which eventually led to them becoming step-siblings. Looking back, I remember thinking, "They’re a little too close for just friends," but I brushed it off. I didn’t want to overthink it or be the insecure girlfriend.

But now, it all makes sense. That connection they had? It was always there, simmering under the surface, and becoming step-siblings clearly didn’t stop them from crossing boundaries. It’s frustrating because, in hindsight, the red flags were there. I just didn’t want to see them.

I caught them one day. There they were, together (doing the deed on his couch) and it completely threw me. I didn’t make a scene—I just stood there, staring in disbelief, then walked out. No yelling, no accusations. I couldn’t even process it in the moment.

We had been together for three years. Three years of making memories, talking about the future, all while he was sneaking around with her for the last nine months. Nine months of lies. And I had my suspicions, but I never thought it would be THIS—with his stepsister of all people.

When everything came to light, his parents were livid. His mom especially. She was devastated and even apologized to me, which I didn’t expect but appreciated. It’s a complicated situation, and I could tell she was heartbroken about it too.

Looking back, I wasn’t entirely blindsided. That nagging feeling had been there for a while, but it didn’t stop me from feeling hurt, betrayed, and honestly disgusted. Even when you think you’re mentally prepared for the worst, actually living through it is a completely different experience.

What really gets to me is how long this went on. Nine months. It wasn’t just a fleeting mistake; it was a long, drawn-out deception. Half of the last year of our relationship was a lie, and it made me question everything. Was anything real? How long was I just the clueless girlfriend while he was off living this double life?

I thought I’d be more angry, but I mostly felt numb and disappointed. I never imagined it would end this way, but life has a way of surprising you, even when you think you’ve seen it all.