To be a bit annoyed my trip has been hijacked?

What an absolutely bizarre comment.

Definitely go tomorrow.

How rude and cheeky to accuse you of causing stress!

Going forward, keep your plans to yourself.

Entitled and rude comes to mind.
Do not tolerate it.

Enjoy your day out.

Meet them there. If ds is a young adult that isn't confident travelling without you it'll do him good.

Train app literally walks you through the journey and what platforms etc. I would stand firm they join you later. If the gf works and they are in a relationship, I think between them both they can achieve this. Its a good learning opportunity.

It's not for your son to decide if two hours is long enough, so I'd tell him that and firmly conclude that this time it won't work for you all to go together, so you'll be going alone. You'd be happy to go together another day, instead.

Or if it's easier, just do what you want before the original planned date, then tell him afterward—but he ought to learn for the future that you not wanting to change your entire day from the original plan is not 'creating stress'. His drastic (albeit not ill-intentioned) changing the plans is what's stressful!

I think I'd arrange a separate outing with both of them, somewhere nearer and treat them to lunch. On a day when GF is not in need of a sleep in aswell.

Then I'd stick with my original plan. Maybe give them a few quid to have a pizza in town instead or something. Stick to your guns. They'll get over it, and will look forward to the substitute day out instead. Well that would be the plan!

If someone can’t navigate the train network I doubt they have capacity to get married

Suck it up this time but make it very clear that the next occasion you’ll be leaving early as planned and they can join you later.

I have suggested we go another day so that we could have more time and was told I was creating stress for no reason and that it would be enough time.

This is extremely unfair of the person who said it. You planned a solo trip. In this case, you didn't mind your son and his girlfriend coming along, but neither of them should have assumed that; it would have been perfectly reasonable if you'd gone alone and said "sorry, maybe next time" to them. When you agreed to company, it was on the trip that YOU had planned, and had accurately described to them. Leaving at 2PM to spend a few hours before closing instead of leaving early in the morning and spending all day would make it a substantially different trip, not the one you chose, and substantially less pleasant /more stressful for you. You might also be reasonably irked because the reason for the proposed change is not an ACTUAL conflict but a desire to sleep in rather than rearrange gf's schedule to accommodate both work and the early departure.

I would at this point tell son that you're going on the trip at the original proposed time and that he and or his girlfriend are still welcome to join you. If not, maybe suggest another outing for all three of you with advanced planning so you can choose a day and times that work for all of you. I'd only pay if you can genuinely afford it and want to treat them; it's certainly not an obligation but make it clear in advance.

(If he's the one who told you you were "creating stress for no reason", I'd also consider telling him that nobody like a mansplainer suggesting that he learn to be civil when asking for a favour. But you know best if that kind of guidance would be helpful).

OP given that your son is neurodiverse, maybe he doesn’t understand how unreasonable he’s being. You’d be doing him a favour by explaining that whilst you’d love him and his girlfriend to join you, the event is something you want to spend the whole day at, so his suggestion doesn’t work. He needs to learn that if you invite yourself to join someone’s planned activity, you can’t then change the schedule.

Agree with this. My son has been doing trains alone since he was 12. If he is old enough to navigate a relationship, he can navigate a bloody train.

Oh fuck no.

They're welcome to come - at the time you are going. If that does not suit them tough tittie, they can come another time.

That is sufficient generosity given the needs/factors involved here.

Read the OP's posts and it might dawn on you.

Heh...with all due respect, this is quite funny.

"This may be your future daughter in law."

Then her future daughter in law will have to go another time. OP had made plans already.

First post nails it as per.

Old enough for a girlfriend ! Then old enough to work the bloody train schedule.. what’s the worst that can happen ? Stop mollycoddling your son and start telling him you have plans that HE needs to fit around.

I wonder whether your DS is a bit torn between your plan (that he would personally like to go along with) and his GF’s stated preference OP? DS may need some help with working out how to assert himself with the GF. Sounds as if he might be trying hard to please everyone and ending up pleasing nobody, least of all himself at the moment.

Surely ‘young adult’ DS and his (presumably similar age) girlfriend can navigate the trains to join you later. My 14 year old could manage this!
That’s the most logical solution. You go first, they join you later.

I'd be pissed off at being expected to rearrange my trip around my son's girlfriend's sleep schedule. I'd say 'not this time'.

We wonder why certain young adults are so self involved - it's no wonder when you read things like this. We're supposed to be thrilled and delighted, make ourselves subservient to their wishes - and of course open our wallets - all for the thrill of having them go somewhere with us. Fuck that. I think parents need to have more self respect and get on with suiting themselves, most modern parents will have done little enough of that for at least 18 years.

Yes seriously. Neuro diverse people have relationships. So do people with learning difficulties.
What's your issue with it?

Don't let your boy tell you these things. Fuck that. Be a role model. You want to come, you do this. Or nothing.

Their request is very unreasonable.

They both horned in on your planned day and then have the nerve to try to make you change your plans. How rude!

If your son is old enough to have a gf, they can have a day trip date without you doing all the work for it and changing your plans to facilitate the gf much less paying.

Tell them no. You leave on your planned train and have your day and if your son dares to say one thing tell him it's rude to horn in on a person's planned activity then try to change the whole plan because his gf decided a little afternoon trip would be nice.

You are not their date facilitator.

I've voted that you are being unreasonable because you just tell the time you are leaving. We are a neuro divergent bunch here. We would say this is our/my plan, there may be some flexibility but we decide what that looks like. We would also say "it'll cost you..." !