Sister Dates My Ex: Should I Skip Her Wedding?

A 29-year-old woman is about to walk into her sister’s wedding day, and she’s already bracing for impact. Not because of the dress drama or seating chart chaos, but because she just found out her sister, Lily, has been secretly dating her ex, Mark, for six months.

Mark and the OP broke up a year ago after a messy breakup that left real emotional bruises. Lily knows that history, and she still didn’t mention a thing, which makes this feel less like “moving on” and more like a betrayal wrapped in wedding glitter.

Now the OP has to decide whether to show up and smile through it, or skip the ceremony entirely.

Original Post

So, I'm a 29F and my sister, let's call her Lily, is getting married in a few months. We've always been super close, and I was genuinely excited about her big day.

However, things took a turn when I found out that Lily has been secretly dating my ex-boyfriend, Mark (32M), for the past six months. Mark and I broke up about a year ago after a messy breakup and it took me a long time to move on from that relationship.

Discovering that Lily, of all people, is now with him feels like a huge betrayal. She knew how much I struggled after the breakup and how much it hurt me.

She never even mentioned anything about their relationship. When I confronted her, Lily tried to downplay it, saying that they just clicked and it wasn't planned.

But the more I think about it, the angrier I get. It's not just about them dating, it's the secrecy and dishonesty that hurt the most.

Now, I'm torn. On one hand, I want to support my sister on her wedding day.

On the other hand, I can't bear the thought of being around Mark and pretending like everything is fine. WIBTA for refusing to attend Lily's wedding after finding out about her relationship with my ex-boyfriend?

I feel like I'm stuck between loyalty to my sister and respecting my own feelings.

A Complicated Love Triangle

This situation dives deep into the emotional complexities of relationships. The OP's sister, Lily, dating the OP's ex, Mark, is not just a simple case of moving on; it’s a direct challenge to the familial bonds that are supposed to be supportive and trustworthy. It raises the question: how can Lily be so casual about her sister’s feelings, especially with a wedding on the horizon? This dynamic can breed resentment, and it’s easy to see why readers feel sympathy for the OP, who’s facing a cocktail of betrayal and confusion at what should be a celebratory time.

The wedding serves as a backdrop that amplifies these tensions. It’s one thing to navigate the messiness of past relationships in everyday life, but when a family member becomes involved, it adds layers of obligation and expectation that are hard to unpack.

The second the OP confronted Lily and Lily tried to play it off as “they just clicked,” the whole thing stopped feeling casual and started feeling personal.

Comment from u/coffee_lover42

NTA - Your sister dating your ex without even telling you is a huge betrayal. It's understandable that you're hurt and conflicted about attending her wedding. Your feelings are valid, and you have the right to prioritize your emotional well-being.

Comment from u/catwhisperer_99

D**n, that's a tough situation to be in. I can't imagine how hurtful it must be to have your own sister date your ex without even being honest about it. NTA for feeling upset and considering not attending the wedding. It's a lot to process and you need to take care of yourself first.

With Lily’s wedding months away, the OP is stuck picturing Mark in the same room, acting like nothing ever happened between them.

Comment from u/rainbowsparkles

Honestly, I don't blame you for feeling betrayed by your sister's actions.

Also, consider the sister who got left out of the bridal party, and whether she should skip her sister’s wedding after the snub.

Comment from u/guitarhero87

That's rough, OP. Your sister dating your ex behind your back is a serious breach of trust. Your feelings are completely valid, and it's okay to prioritize your own well-being in this situation. NTA for considering not attending the wedding.

Every time the OP remembers how Lily knew about the breakup pain and still kept Mark hidden, the anger gets louder than the “bridesmaid” excitement.

Comment from u/thebookworm

I can't even imagine the mix of emotions you're going through right now. Your sister dating your ex without even discussing it with you is definitely hurtful. Your feelings are valid, and it's important to take care of yourself. NTA for contemplating not attending the wedding.

What do you think about this situation? Let us know in the comments.

So when the OP asks herself if she’s wrong for refusing to attend, it’s really about loyalty to Lily versus protecting her own sanity around Mark.

Community Reactions: Divided Loyalties

The Reddit community’s reaction to this dilemma underscores just how varied perspectives can be when it comes to family loyalty. Some commenters argue that the OP should attend the wedding for the sake of family unity, while others firmly believe she should skip it as a form of self-respect. This division highlights a broader conversation about personal boundaries versus familial obligations.

Many readers resonate with the OP’s feelings of betrayal, especially considering the emotional investment that comes with dating a sibling’s ex.

The Takeaway

This story captures the messy intersections of love and family, and it raises a compelling question: when is it okay to prioritize your feelings over familial ties? It’s a dilemma many can relate to, and the reactions show just how personal and varied these experiences can be. How would you handle a situation like this? Would you put family first or protect your own emotional well-being?

The Bigger Picture

In this emotionally charged situation, the original poster grapples with feelings of betrayal after discovering her sister, Lily, is dating her ex-boyfriend Mark, just months before her wedding. The secrecy surrounding their relationship amplifies her pain, as she feels betrayed by someone she thought would be supportive during her difficult breakup. This scenario highlights the complex dynamics of loyalty and trust within families, as the OP must weigh her emotional well-being against her desire to support her sister during what should be a happy occasion. Readers can empathize with her struggle, recognizing that prioritizing self-respect in the face of familial ties can be a deeply personal and challenging decision.

The wedding might be Lily’s big day, but the OP is the one who has to decide whether she can survive seeing Mark there.

If you think Lily and Mark is messy, see why a brother picking your ex as maid of honor becomes a wedding bombshell in this AITA case.