To feel sad about this?

The OP is behaving as though she’s Kevin in Home Alone, only the parents did it deliberately.

Ignore that poster. Some people don’t understand subtleties and emotions. Life and humans aren’t just about spreadsheets and cold logic.

Would you not be able to stay with your brother at all?

I’m sorry OP. How is your relationship with your parents in general? It does seem weird for them to say ‘it’ll be a family Christmas’ to you if they know you’re not coming. TBH I think it’s understandable they’re excited and I don’t think they’re wrong to go, but it sounds like they could be handling it more sensitively. Is there tension between you in general, do you think they are possibly getting a bit fed up with you being at home? If rent would be the same for living independently, I’m not sure I totally understand the advantage of you staying with them, unless you just get on well and enjoy each other’s company, in which case fair enough?

I can well imagine that it feels shit right now when the news is new, but as others have said it’s also an opportunity to start building your independence and your own traditions. Are you dating? I would have thought at your age you might possibly have met someone by Christmas and find you want to spend it with them anyway? But if not, I’d be looking for cool unusual things you could do - maybe go for a Christmas Day service at somewhere beautiful like Bath Abbey or Westminster Abbey, where you’ll have other people round you to sing carols with?

Sigh. Look at it this way. It was never going to be an all-family Christmas this year. At least one family member was going to be absent. Why does it need to be your brother rather than you? You seem to be suggesting your parents should prioritise you over your brother. Why?

I’d be excited to go if I were your parents however I do think they’ve been a bit tactless in the way they’ve handled it, shrugging their shoulders when you mentioned being on your on at Xmas is a bit sad. I’d still go to Australia but I would have been a bit more thoughtful in how I handled it.

In the nicest possible way, there are ways of saying what you’re trying to say without being awful. I would suggest you learn them, since you are after all a grownup.

This is awful op I really feel for you.

Firstly £600 quid a month is appalling, they clearly aren't short if they can afford this trip.

To leave you home alone knowing fine well you don't have extended family is shit too. He's only going for a year! Are they usually self absorbed arseholes or do they have redeeming features?

You just need to carry on saving, move out asap and find a way to power through Christmas

I think you are right not to spend your money and going but if you have to accept either you or your brother will be alone.

You will save money on not buying them any Christmas presents this year.

Between now and then, buy yourself some till treats to open, but wrap them immediately you get home so you have some things to open. You will have forgotten what they are by then.

In December get out some of your parent’s decs and buy yourself favourite snacks.

Have a luxury pizza for lunch and enjoy a few days off work.

Enjoy pleasing yourself for the day.

There's no reason you can't get a Christmas tree, or you can't go to work when jetlagged. Why would the house be colder just because your parents are on holiday? I think you're hurt and trying to put up obstacles.

Focus on the positives maybe? You have a job and a nice home, savings in the bank and a family you see (even if not at Christmas).

That’s fine, but it’s your choice.

Respectfully, that would make the OP sound even more whiny, self-pitying and teenage than she does. And yes, I appreciate she’s chosen to do that online, rather than to her parents, but it’s probably perfectly obvious she thinks they shouldn’t be going because of her. Which is pretty self-centred.

My parents have gleefully announced that they will be travelling down to see him at Christmas

Should they announce it sobbing and crying?

They’re going on holiday, for heaven’s sake! To somewhere your brother happens to be going to live. Do you normally expect to go on holidays every time with your parents? Or do you think that because this extended holiday includes Christmas it’s different? You’ve said yourself you couldn’t go, even if money were no object or if they paid for your flight — you don’t have enough annual leave. So is what you want for them not to go?

Nonsense! Of course you can do christmas on your own or volunteer at a charity, or organize a Christmas with friends. There are lots if options. Time to take your own life in your hands and build up friendships outside your family.

You're an adult. It's one day. Christmas happens every year.

It sounds like it's a trip of a lifetime for them but you don't want them to be excited infront of you because it'll make you sad?

Can't you try and be happy for them?! They're your parents! They've spent years bringing you up and you're still at home in your 20s. They deserve some time to do what they fancy and when.

They’re saying that him going to Australia won’t stop them having a “family Christmas”, while one member of the family is left behind
Ouch, that's got to sting. I've spent decades putting everyone else's wants first at Christmas (even had a thread about it) so couldn't imagine doing what your parents are doing.

Anyway, not much you can do about it other than make other plans. Look at Meetup groups as a previous poster suggested, or local charities. Put feelers out for friends in the same boat. Over the years we've hosted the odd friend of our adult DC or a lone niece or nephew at a lose end. Perhaps rebuild bridges with your extended family?

I'm not saying that I agree with them but could this be some misguided attempt at encouraging you to be more independent? There's a lot of talk about helicopter parents and failure to launch which can play on some parents minds.

It's shit but I'd take the fact that you've got almost 6 months notice as a positive as that should give you time to process it and look at what you could do to get through the season by yourself. Some of your friends might suprise you if you ask or else have a read on here, there's some interesting threads where people talk about solo Christmases.

But, why arent you responding 'im sure itll be lovely for you but I will have a very lonely christmas on my own with no family, so thanks for that' or 'nice that you feel its a lovely family Christmas without me there, how do you think that makes me feel?!' why are you not at least making abundantly clear how you feel? Who cares if they claim you are being selfish, id just say no i am not being selfish, you have ruined my christmas and im entitled to feel very upset by that'.
You dont have to pussyfoot about and not tell people when they have really hurt you. Speak up

its very sad for you. could you maybe book a few nights in a hotel over Christmas? I would do that and then read some nice books, go for walks etc? Its not the same as family Christmas but better than being at home alone

It’s still family time when one person isn’t present - families don’t have to be together 24/7 or not enjoy themselves if others can’t or don’t want to do stuff.

It probably isn't! But, it's still a decision of your own to make and then cope with.

I promise, there's a real liberty in owning all your own choices about how you want your life to be. Feeling like a passive recipient of other people's decisions is horrible. You aren't powerless, you're making a wise choice that the house deposit is worth coping with Christmas without family.

You could move Christmas and do a friend celebration on another day? I guess you don't do a job where you could volunteer to work and make a lot of extra pay?

When I asked what about me at Christmas, they shrugged their shoulders.

With all due respect, you are in your 20s not a little child.