Am i overreacting to these rules?

I can't believe they have asked this of you! If they had a short gap between getting engaged and getting married, then I could maybe see why they wouldn't want you to suddenly announce that you're about to have a wedding just before them. They certainly can't control your lives for 4 whole years though, and they shouldn't have ANY control over when you choose to have children!

If you can hold off getting engaged, your partner could always propose at their wedding...

Your partner's brother and girlfriend are delusional.

When you get married, you get a day. One day. You do not get to control the lives of those around you for a whole four years.

Get engaged. Start planning that wedding. And if you want a family, the sooner you start thinking about it the better. You don't want to be sitting there in 20 years time thinking "too bad we left it too late to have a family - but never mind, at least we kept brother-in-law happy".

And anyway, what's to say that once this crazy pair have got married, they won't be telling you that you can't get engaged/married/start a family yet because they are planning to start a family/change careers/move house/paint their bathroom and they don't want you 'taking the spotlight' off them.

This is wild! I've never heard anything so ridiculous, I certainly would not be listening to what they have to say either. Like it has been said above, they have one day to get married, that is all. They can't expect you to put your lives on hold for 4 years!

Oh my god are they SERIOUS? This is the most ludicrous thing I've ever read. You get married and have kids when it's right for you. I understand wanting to keep everyone happy but you can't put off having a family to spare someone else's feelings.

Book a 2023 wedding and tell them to deal with it. Eventually they'll get over it.

This is awful - if you are also wanting a family, as you mentioned, I would 100000% plan your wedding know, if they have chosen a longer engagement that is there choice. I wouldn't go for the same season in the same year, but that is the length of patience and respect I would show on this in all honesty. Get married how you want, where you want, when you want ASAP. I am not one for my way of the high way when it comes to weddings, as I think family is important, but this is beyond the line. Don't put your life on hold, or your future hopes of a family at risk for the sake of a soon to be in law family.

Book it for 2023 and tell her to get stuffed.

That seems absolutely ridiculous to me. My best friend (and maid of honour) had a situation when she got engaged where her two brothers and her fiancé's brother all proposed around the same time. They all coordinated so that everyone could have "their moment," but the agreed waiting time between engagements was 2 WEEKS. Asking someone to put their life plans on hold for YEARS is incredibly selfish and not at all realistic. It's simply unhealthy to believe you can place those kind of restrictions on people.

I'm the oldest in my family and first to get married, and I have 3 younger siblings. I cannot fathom putting that kind of rule on my siblings, and my engagement is only going to be 9 months total. I would go ahead with your wedding/life planning. I hope all goes well.

Selfish and unrealistic expectations from your bro and sis in law to be! You cannot listen to this and have to do what is right for you as a couple or risk living to regret it.

"My partners mum has tried to talk to them both and has tried to explain how unreasonable they are being. She was shut down immediately and they didn’t talk to her for 2-3 weeks after the discussion (the only reason they talked was because they wanted something of my partners mum)."

Ok, so I understand why your partner doesn't want to fall out with his family. But think about it this way.

Is it really going to have that much of a negative impact on your lives if this pair do react badly to you getting engaged and/or married before their wedding? And is it really worth putting your life on hold, potentially losing your ability to start a family and risking not having elderly loved ones around for your wedding just so that they don't fall out with you? It sounds like they only talk to people for selfish reasons anyway.