Dating My Exs Sibling: AITA for Keeping it Secret?

Emily and OP were done, officially and on mutual terms, but the breakup didn’t exactly close the book. Because while OP moved on with Lily, Emily’s sister, he quietly kept that part off the radar.

OP is 27M, Lily is 25F, and the messy twist is that Emily already knew Lily had a crush. Still, OP didn’t tell Emily he and Lily were dating, which might sound like “no drama” until Emily spots them together in town and flips out.

Now Emily calls OP sneaky and feels betrayed, and OP is stuck wondering if silence was protection, or just the start of a bigger family mess.

Original Post

So I'm (27M), and I recently started dating my ex's sister (25F). We broke up with my ex, let's call her Emily, about a year ago on mutual terms.

I always knew her sister, let's call her Lily, had a crush on me, but we never really talked much until after Emily and I ended things. Lily and I hit it off, and eventually, we started dating.

For background, I never told Emily about my relationship with Lily. I guess I didn't think it was necessary since Emily and I moved on, and I didn't want to cause unnecessary drama or hurt feelings.

A few days ago, Emily found out about Lily and me when she saw us together in town. She was furious and felt betrayed that I didn't mention anything to her.

Emily accused me of being sneaky and not respecting her feelings or our past together. So, AITA for not telling my ex about dating her sister, or was it justified since we had already moved on?

The Sibling Dilemma

This situation dives deep into the murky waters of relationships and family dynamics. Dating a sibling of an ex isn’t just a romantic choice; it’s a potential landmine for family ties and friendships. The OP’s decision to keep this relationship with Lily under wraps raises eyebrows. Was he protecting his own feelings or avoiding a confrontation with Emily? The lack of transparency could indicate a fear of conflict, but it complicates the situation for everyone involved.

Moreover, considering that both women are sisters, this could easily lead to feelings of betrayal or jealousy. The OP might think he’s found a genuine connection with Lily, but without honesty, he risks alienating not just Emily but potentially causing rifts within their family. This tension is what makes the story resonate so strongly with readers—many have likely faced similar dilemmas in their own lives.

Emily’s anger wasn’t random, she saw OP and Lily together in town and immediately connected the dots.

Comment from u/random_throwaway123

YTA - Bro, not telling your ex about dating her sibling is hella shady. That's a recipe for drama. Should've been upfront.

Comment from u/gamer_gal99

NTA - You and your ex were over, so you don't owe her updates on your love life. It's not like you were secretly plotting this.

Comment from u/coffee_addict_87

YTA - Dude, family dynamics can get messy, and not disclosing your relationship with Lily to Emily was pretty careless. Things could've gone smoother if you were honest upfront.

Comment from u/bookworm_luna

NTA - People break up, and you're allowed to date whomever you want after. It's not your responsibility to update your ex on your personal life post-breakup.

OP figured moving on meant no need to mention Lily, but Emily reads that as hiding something.

Comment from u/travel_bug92

YTA - Ignoring potential fallout from not informing your ex was a bit naive. Relationships within the same family can stir up intense emotions, and communication would've been key.

This is close to the AITA where someone dated their friend’s ex, but kept it secret.

Comment from u/pizza_lover365

NTA - Once the relationship with Emily ended, your dating choices are your own business. She doesn't have a say in who you see after the breakup.

Comment from u/sunset_watcher

YTA - It's always better to be transparent, especially when it involves family members. Not telling Emily about Lily was kind of asking for trouble.

Lily and OP went from “we never talked much” to dating, while Emily is left feeling blindsided by the timeline.

Comment from u/icecream_fanatic

NTA - As long as you treated Emily respectfully during and after the breakup, you weren't obligated to disclose your relationship with Lily. Your love life, your decisions.

Comment from u/anime_freak18

YTA - Relationships like these can be delicate, and honesty is crucial. Keeping Emily in the dark about dating her sister likely felt like a betrayal of trust to her.

Comment from u/singing_rainbows

NTA - Once things are over with an ex, you don't owe them updates on your personal life. Emily's reaction seems more about her feelings than your actions.

After Emily accused him of disrespecting her feelings, the whole question becomes whether OP had a good reason to keep it secret.

What's your opinion on this situation? Join the conversation!.

Why Honesty Matters

The divided opinions in the comments reflect a broader societal debate about honesty in relationships. Some readers argue that the OP should’ve come clean before pursuing Lily, emphasizing that transparency is crucial in maintaining trust, even post-breakup. Others sympathize with the OP's desire to move forward without complicating an already sensitive situation.

This highlights a key contradiction: when is it okay to prioritize personal happiness over potential hurt feelings? The OP’s choice to keep the relationship a secret raises questions about whether self-interest trumps familial loyalty. This complexity is what fuels the discussion—viewers can relate to the push-and-pull of wanting to respect past relationships while also trying to find new love. It’s a real-life reminder that relationships often exist in a gray area filled with conflicting emotions.

The Bottom Line

This story illustrates just how complicated relationships can get, especially when siblings and past partners are involved. The OP’s choice to date Lily without informing Emily touches on themes of honesty, loyalty, and emotional self-preservation. It raises the question: when it comes to love, how much honesty is too much? Readers are left to ponder their own boundaries and what they would do in a similar situation. What would you choose—love or transparency?

What It Comes Down To

The situation between the Reddit user and his ex, Emily, highlights a classic conflict in relationships: the balance between personal happiness and honesty. By choosing to date Emily's sister, Lily, without informing Emily, he may have thought he was avoiding unnecessary drama, but that decision ultimately backfired when Emily discovered the truth. This dilemma forces us to consider how transparency can sometimes be the best approach, even when it feels uncomfortable.

The family dinner did not end well, because OP’s secret turned into Emily’s full-blown betrayal.

Emily’s sister Lily dating her ex is nothing compared to the guy who set up his friend with his ex, now dating his sister.