AIBU to be furious FIL called my son a burden at my own wedding?

*in their old age

That is true.
People get very incensed about feelings for children, but children are just people after all. There is no reason that they have or should be loved by others.

And no unique morality that says not doing so is vile. There are many morality systems in the world.

By the same token cultures where their morality is that adult children take care 100% of parents in their old could call those in western countries who might also use carers or nursing homes disgusting.

There are many morality systems in the world.

Possibly yes but you keep it to yourself, keep your nose out of their business and hope that they can all make a go of it and maybe help if you're asked.

Wouldnt most people, if they are honest, prefer that their son /daughter did not marry someone with baggage

They're awful people. You're both better if without them.

This is why, on other threads people say that step children shouldn't be lied to and told that their step families think they are as close as biological relatives. In a divorce or separation, the truth is instantly revealed.

I'm sorry it's happened this way for your son. It's brutal. At least he no longer has to share a life with someone who doesn't value him as a person.

@IAmBreathing when my XH decided he wanted a divorce, I was effectively dead to my MIL from that point. FIL was a bit better, but MIL was awful e.g. sending Christmas cards addressed only to DD, refusing to make eye contact / speak to me on the rare occasions they collected DD to take her somewhere. MIL also started treating DD like a Mudblood, an inferior grandchild because of my genes.

I bore with it for a while, then wrote her a letter detailing exactly what a cow she was being, and why I was delighted never to have to see her, or her side of the family, ever again. I may also have returned some Christmas tree decorations that I didn't want hanging from my tree ever again. Zero regrets about doing this, and I feel completely happy with my decision. Since then, I've only seen her once and she was clearly on her best behaviour. So I say, if it would make you feel better, then go for it.

I think your ex sounds so cold and callous, almost unbelievably so. But the original subject of your post, a comment the FIL made at the wedding....well it isn't great at all obviously and clearly he shouldn't have shared it with a stranger but to be honest, I would prefer ALL THINGS BEING EQUAL if my children married people who didn't already have children. For exactly the kind of scenarios which so often seem to arise of divided loyalties, some children being treated as lesser, bonds being formed which are dependent on a couple staying together, etc. It can be wonderful but it can also be messy and tough and can most definitely end in tears. I know of plenty of cases where in-laws did everything right, formed attachment to step grandchildren, nieces, nephews etc only to lose that when a couple breaks up. The inlaws sound unpleasant but your main issue surely is with the horrible ex

The first response nailed it. ExH is a cunt and so is his dad.
I'm so sorry for your son who has had this twat of a man as his "dad" for 10 years. It is time to step up now. Put your son first, trust your instincts. You are enough for him - one good parent to have his back is better than an extended step family excluding him and having his mum doubting herself.
ExH and his family are the losers here.

How could anyone live with, help bring up and form a bond with a child from the age of 4(?) and then walk out and not speak to them?!
You have to be a very special type of selfish, cruel bastard to do that.
You are better off without him and the rest of the people he calls family.
Family love is unconditional, they are not your family. You and your son deserve more, he will be better off without that influence in his life and you sound like you're doing a great job .
All you can do is offer him as much support as possible, be honest and listen to him if he needs to talk - which I'm sure you're doing already.
And don't hesitate to talk to someone yourself, it must be incredibly hurtful to hear people have said such horrible things.

... and ignore any past or future comments here from bitter stepparents who think this is normal. It's absolutely not normal and stepparents who say tgis will say do so to normalise their own unloving behaviours. Most stepparents in real life are loving and caring people working hard to have a blended family. I do love my stepchildren and for me they're no different than my own biological children. If I didn't I would divorce. Treating stepchildren, especially ones you lived a long time with, you raised, especially children, as second class citizens and normalising this is cunty behaviour.

In short

your fury is too little, too late and directed at the wrong person

Well your son is likely to be better away from that mean spirited family.

What was he like as a husband for the past 8/10 years OP?

Oh sorry - I see you don’t have kids with him.

I still think you need to focus on the future though, I don’t think there’s any point bringing it up.

Did he have any children?

I am sorry your OH’s family weren’t nicer to him.

There’s no point mentioning this to your ex now - it’s really important that you focus on the future with him for the sake of your younger kids.

She was with him 12 years in total
Dated him for 2 years.
They then moved in together
2 years after living together they married
They divorced 8 years after that (recently). Her son from former relationship is now 16. He was around 4 when they met and 6 when they moved in together and 8 when they married and FIL called him baggage. After 8 years of being his legal step dad he's left mum and sent 1 text. That's it. Just walked.

I think your uncle did you a favour. You now know what ex FIL really thought and what the rest of the family did too no doubt. You also now know your suspicions over their treatment of your son were justified and it wasn’t a figment of your imagination.
cunts the lot of them.

Did you read the OP

absolutely nothing to be gained from telling the OP this only to upset her.

shit stirring at its finest

I’m surprised by the answers on this thread so far. People typically want their children to have the easiest lives possible. Step-parenting is far from easy. It can be worthwhile and it can build wonderful families, but a relationship without pre-existing children is simpler.

Being worried about the situation their son was marrying into is logical.

as for not being welcoming once the marriage happens, that is an asshole move. the best way to help your child with their step-parenting journey is by doing the best you can to blend the larger family.

So he’s hardly likely to start believing you now that he’s ended the marriage

I often felt that my H's family were mean spirited towards my son, judged him harshly, didn't properly consider him and ignored him a lot of the time. We holidayed a lot as an extended family (H's choice) and this was especially apparent when on holiday. I felt he was in the way at times and as he got older I often felt hurt by the lack of feeling towards him despite him making every effort to fit in and meet their approval.

YOU were his mother OP. And you forced him to endure this family, even for his holidays, year in and year out for pretty much all of his childhood. You failed him op

@Fififo42 eh?