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Is it weird that my younger brother is dating my wife’s younger sister?

77 replies

kfyuy · 07/09/2026 10:34

Me and my wife are both in our mid40s and have been married for 18 years. We have 3 kids.

I have a younger brother (38) and younger sister (42). My wife has an older brother and sister, and a younger sister who is 38.

Anyway… my younger brother and my wife's younger sister have apparently been dating for a while. Both have children from previous marriages my brother has 2 kids and her sister has 3. All the children are under 10 and roughly similar ages.

I only found out yesterday at dinner, when my wife casually announced that they were a couple. They were both there too. Apparently they're quite serious and are planning to get married.

And yes, I realise everyone involved is a fully grown adult and they're not doing anything wrong. I genuinely want them to be happy.

But I can't help thinking… isn't this a bit weird?

My little brother potentially marrying my wife's little sister means our families are suddenly going to be even more intertwined. We'd effectively become in-laws twice over, and our kids would have their uncle married to their aunt.

Maybe I'm overthinking it, but finding out about it at a family dinner, and being seemingly the last person to know, has left me slightly bewildered!

OP posts:
ginasevern · 08/09/2026 14:08

@kfyuy I think it's the thought of your own brother sleeping with someone who is genetically the same as your wife. That's why you're finding it weird.

Luddite26 · 10/09/2026 08:40

JasperHale · 07/09/2026 10:44

My Grandfather's brother married my Grandmother's sister. Best thing ever.

My gran and her sister married my granddad and his brother. Super close cousins big family dos back in the day. All Buried next to each other now.

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