Am I a laughing stock?

How fabulous for these people that they have no other greater concerns to fill their day.

Probably not.

I remember my mum blowing up at me as my friend and I used to refer to ourselves as Goddesses. This was very much tongue in cheek, I've never been remotely pretty.

She ranted on about how I definitely believed it, and how could I utter such words about myself like that.

There's a similar vibe in some of the responses here. It's just so innocuous

Your mum and sister sound vile.

Personally, I find it fine and light-hearted. Nothing cringey about it at all. Is it really all your friends can find to laugh about?

Just keep going the way you are. Ignore them. If you change now, they will assume they have control over you and you don't want that to happen.

Thumb your nose up at them. I cannot see anything wrong at all. I suspect they don't either. If you change through embarrassment they will see they have won over you and will look for something else to make you unhappy.

Such people should never be appeased. They are NEVER satisfied. Give them an inch and they take a mile. Stick to what you do. There is nothing wrong with it, and many other people do the same.

(and she only has her spiteful sister's word for it that they've all been "slagging" her off for it)

"Slagging" was OP's word, not her sister's.

Also, OP's friend tried to be subtle about the fact that other people find it tiresome too. So it's not just her sister and her mother.

OP, as you seem to have made this "jokey" house name a large part of your character, perhaps people felt awkward about telling you it was wearing thin.

Please don't be afraid to have a personality! It is a joke.

Your sister sounds like a real charmer. Lucky you. I have one of those too! 😂

"Why don't you bring them back to the Towers ..?" As your sister, I'd expect you to say " why not bring them back to OURS". Sorry but that does make you sound so far up yourself! Is your house big? Do you flaunt wealth? At least you know to stop now.

Well said.

It’s horrible that your sister and Mum could be so mean OP, I’m sorry that your feelings are hurt.

I don’t see anything at all wrong with it, it’s just a joke. If people want to be mean about it that is their problem not yours, just keep on with it and annoy them even more!

DOUBLE DOWN, OP.
Tell your family they’re right, then upgrade it to CASTLE [SURNAME] 🏰
Tell them the staff will have the flags hung out for their next visit and that you shall all dine on SWAN. Answer the door in a ballgown.

We called our house Foocombehall.
Another house Crap palace.

Ignore them. My friend calls my house Scotland32 Towers just because it’s bigger than her house. It’s all tongue in cheek. It would only be w*anky if you really did live in a mansion and were boasting. If you live in a normal house then surely everyone knows you are joking?!

I’m genuinely surprised that so many people would care to this extent about a silly in joke amongst friends and family. Also, not all silly things are deliberate attempts for attention or to appear a certain way to others - some of these things happen organically and just become part of the vernacular. We have all sorts of stupid shit we say as a family and with friends - it’s the sort of thing that develops alongside a deep bond and understanding between a few people. Op - I’m sorry your sister was nasty about this, please don’t change what you do.

Many years ago when my mum was a widow and me and my sisters were living at home and in our late teens and early twenties....a male friend of the family christened our house. Tit Hall...even the cat was female

Alongside the other ‘we’re so wacky and fun’ stuff. 😄

If it is good enough for Donald?! .....

In her hall, not on her front door.

It's not "only the OP keeping the joke going" - she wrote in her opening post that some of her friends use it too (presumably the ones who still find it funny or are willing to humour her because they're genuine friends).
So, going back to OP's original question "AIBU to think someone might have mentioned it before now?", she's NBU - why didn't they? If they've found it so unfunny for years why didn't one of them tell her years ago? Alternatively, if "everyone knows it's a joke" why don't they continue to treat it that way? (Or, at least, tell her kindly it's wearing a bit thin now.) It's clear that OP's sister, DM, other family and (maybe) some so-called friends just aren't very nice people.

The answer to why has no one said is because it's the sort of thing that gradually becomes irritating rather than it being immediately worth a reaction.
First few times, you might internally roll eyes, but when it becomes clear they're taking it more seriously (and let's be fair, putting it on invites does mean you're taking it seriously) you begin to cringe inside every time you hear it.

One of those things that you hope someone else will point out or they'll stop doing it because they realise that the joke's wearing thin.
And any joke wears thin if it's used too much.

Like someone who constantly name drops. The first couple of times it doesn't bother you. But when it's clear that they'll always drop into conversation "my good friend Sir Famous..." it jars.

If it was just your sister, then I'd probably say don't worry. Sisters (and brothers too) can find that sort of thing far more irritating and be far more likely to speak out.
However your friend's reaction tells you a lot more. It's clearly been spoken about and not positively.

Those saying "well they took your hospitality" are not really right. You can like someone; enjoy their company, etc but still find aspects of them irritating. There is no reason to suppose that the people who came didn't like the OP.

I refer to my home as " the ranch". I don't care a jot what anyone thinks when I say "back at the ranch". It seems they are the only ones upset by it. I would carry on and put (Ha! Ha!) in brackets after as signing your card from...... Towers - or emojis on any texts signed off like that.

they didn’t have the heart to tell you it was wearing thin

That's why no one said anything because they do actually care about her. But maybe her sister had got to the point where she couldn't bear to hear the OP say it again knowing that people had got tired of hearing it. And it just came out.

I get it. I'm thinking of doing the same, only Burdock Castle.
As long as I'm having fun, fuck 'em.

I think it sounds fine as a joke and wouldn't worry about it. I might phase it out a bit now though as you probably can't enjoy it in the same way.