Don't want to go out to dinner with this family member.

Well the adults are being poor company if they're unable to include a 14yo in conversations. Also the 14 yo is allowed to be a bit bored.

What's the actual issue, teenagers being allowed to be antisocial dicks staring at their phones whilst with family and friends?

So tell them that's the reason. There's absolutely no reason for anyone to be gawping at a phone during any meal.

They can learn to have actual conversations.

I can’t see anything here I can get my knickers in a twist about. I’m the parent of a 14y old boy and does he sometimes go on his phone if we’re out with family to eat? Yes sometimes because sometimes the adults are chatting about stuff which he has no interest in and cannot join in with. Is he rude and ignores people when spoken to? No. Would I read the menu to him? Absolutely not, but these aren’t your kids so not your issue. Not your circus and all that…..
Unless as others have said you are all splitting the bill? In which case I’d just say sorry but we’re on a budget so will need to just pay for our own. You can still enjoy the rest of the adults company surely? It sounds like you just don’t like the teens very much tbh…..which I get, they can be hard work. But on the other hand they’re quiet so not bothering anyone..

I'm struggling to understand what your issue is @Poodlelove is it because you can't afford to go for a meal? Is it just the poor (agree poor behaviour and parenting) of the teens) or is it because the cost of the meal is shared and not divided based on who ate/drank what which then costs you more to eat out?

I'm just really struggling to understand how them having a pudding affects you personally unless it's to do with how the bill is then split?

Dear family member,
I can’t afford to go out for a meal very often so when I do, I don’t want to have it ruined by rude children like yours. Hope you have fun.
Love,
OP

I've never invited people for a meal then monitored what their teens were or were not eating or ordering. If they're on their phones then fine. Surely you've got adult conversation you'd rather be having than trying to engage unwilling teens in pointless chit chat.

I don't really see how it could negatively affect you in any meaningful way. If they were overly talkative, rude, ordered loads of food and ate messily, wouldn't let you and your friends chat properly, tried to drink alcohol etc that could be annoying too if you let it. So sitting on phones and grunting isn't really an issue for me.

They're not your kids and they just don't want to be there. Not that unusual for teens.

Soon enough they'll probably stop being dragged along to such things and you needn't concern yourself anymore.

Make it clear you’ll only pay for what you eat/drink. Or suggest a take away and do the same, or a pot luck buffet.

I detest food and drink waste, and that’s irrelevant of how much it costs or how affordable it is. I certainly wouldn’t be paying for food and drink others thoughtlessly ordered that they really didn’t need.

It isn't the money and the spending that is the issue it's the complete lack of good manners. I can only assume these teenagers must have learning difficulties if their mother is reading the menu to them.

I'm assuming you're not paying for them? They sound annoying and definitely not the type of guests I'd choose the have dinner with. Having said that, I'd probably just go anyway, so long as all it's costing me is a night out? But if they bother you so much then do as pps have already mentioned and come up with an excuse not to go.

" I know it sounds like we are tight "

It certainly doesn't

Oh dear! Tricky to phrase 😂

Just say:
I’m going to have to skip this one. I won’t be able to make it, but I hope everyone has a great time! Let’s catch up soon in another way/for coffee/for a walk etc
No excuses, no mention of differing finances, no mention of surly teens, just a sorry can’t make it let’s reschedule.

they may not. I actually like my sibs but they have no idea of my income nor I of theirs.

The reason is she’s insufferable! 😅

what will you do next time?

Don’t go, it sounds like it’s expensive for you and you don’t enjoy it, it certainly doesn’t bring you closer to the friends! I wouldn’t enjoy it either because it’s bad parenting and entitled kids ( not for taking a meal out for granted, but for expecting so much of the parents! None of mine are teens and if they expected me to read the desserts to them I’d say clearly you don’t want dessert that much, ok let’s order for the ones who do. Except my 3yo, who can’t read, I think it’s reasonable I help her choose.)

my experience is that if they are going to take offence they will however you phrase it. If you are never going to want to go then "no thanks" is perfectly polite

What's the reason though?
Mostly you'd just put up with minor issues, go along and enjoy the meal. No problem. However, if someone really doesn't want to do something, there's obviously a problem.

As much as I would love to do this so often, I think it could come across as a bit rude to say the least.

EG annoying cousin: “Hey, fancy catching up over dinner?”
Me: “No thank you.”

😆

OR - hear me out - say "No, I think I'll skip it this time."

I think I'd generate a last minute tummy bug/bad back/migraine if I was really that unkeen to go.

Me too. I hate it!

She doesn't need to be rude. Or even blunt.
Just not lie!
"I can't come because it's just too expensive for me at the moment, sorry"
"I don't really feel comfortable with the teens on their phones all the time, it would be nice if it was a more sociable evening, could we meet up without them?"
Or some such.

You haven't clarified who pays. If you aren't paying for the teenagers and they aren't disturbing you by being quiet on the phones, I'd stop thinking about it. If you aren't looking forward to the meal or can't afford it, maybe you should say you don't want to go?

I am not sure what the issue is. You sound a little jealous that they eat out regularly and the teens are allowed to pick and choose what they eat.
As others have said unless you are paying for them, this really isn't your issue. I am guessing the teens are at an age where they don't really want to be dragged along for a family meal and find it boring, hence being allowed their phones.
I am guessing you don't see these family members much hence them wanting to arrange to meet up, but if you aren't fussed about seeing them then just say you can't make it and be grateful other family or friends are attending this time so shouldn't be an issue if you don't go.