If you're sharing the cost of the meal there's certain things you don't go for

Good grief! This sounds like the worst night out ever! Unwritten rules about not ordering too much/ expensive food (clearly there’s not an unwritten rule as he’s not following it), half a shandy, people seething quietly over the main event because someone’s main costs a bit more, then family get “funny” about splitting bill.

Either just stop going, make your peace with it (even if the mixed grill is a tenner more, that’s £2.50 per person), order something equally expansive or just politely stick to your boundaries- maybe just go to the bar and pay for your own stuff and then tell the others what you’ve done, then scarper before they can get “funny”?

I live closer to the restaurant me and my family favour so am often not driving while they are, so I'm the one having 2 or 3 glasses of wine rather than one or none.
I always always offer to put in more £ or pay the tip. Finances are irrelevant, I'm not a CF and if I've used more of the overall bill quantity, I'll pay for it. I agree your BIL is greedy.

That's exactly what all the groups I go out with do which is why I'm asking if there's now a widely available way to make it easier that I don't know about

Stop going out with them or order the most expensive 3 course meal and several cocktails.

I’m a fussy eater and having steak is always my fall back option if there’s nothing else I like. If nobody else has ordered something equal in value, then I will offer to pay more, but I certainly wouldn’t feel forced to order something I don’t want.
I don’t eat dessert but I wouldn’t care if others ordered one and I certainly can’t be arsed to mentally tot up the value of what everyone else has had.

In what way is it tight to not want to subsidise someone who is clearly taking advantage of the fact that hes making everyone else pay more?

I genuinely don't understand that way of thinking, can you explain where you're coming from with that?

There’s clearly not though is there?? If I go out for a meal I’ll order what I want to eat, same as your BIL, if you don’t want to split the bill you need to speak up and say so.

I think you’re made up this ‘rule’ in your own head.

I can't stand people like this. I had a friend like this, clears throat, ex friend.

Give an inch....

I'm of the thought everyone should order what they want, which is why I am not a fan of just splitting a bill and will avoid where possible. I do prefer for everyone to just cover their own costs if it's not one person treating everyone.

If I do have to go to an "equally" split bill meal and I fancy a steak, lobster, or to finish with a nice brandy I will have it, however I always say I am putting into an extra x before the bill calculations start.

Whether or not the rest of the family like it, you can tell the server that you and your partner will take a separate bill. Why on earth would anyone object to that?

Nope, going out for dinner is usually a treat so I’m having what I want. I’m not making my choice because other people are having something cheaper and think there is an unwritten rule you have to do the same. And it’s definitely not greedy either.

If it was massively more expensive and we are splitting the bill I might say I’ll put more in. But I tend to find it evens out over time as next time I might not have something more expensive but someone else will.

If you are on a budget then I wouldn’t split the bill and would pay for what you’ve had.

I've been in that situation. We don't ask for separate bills. We look up the cost of the menu items and tell the server how much to take off each of our cards.

No, there’s not.

It’s something some people do and something some people don’t do.

If you have a problem with it, speak up. It’s bothering you. I don’t understand people who are unhappy about something but won’t do anything apart from sit and hope the other person plays by rules they don’t know exist.

If you are going to a place that has wildly different price points in main courses e.g some at £8 and some at £25 then it's foolish to agree to split the bill at all and each should pay what they owe plus 20% (so that any calculation disparities are just swallowed up by a slightly variable tip which should end up at least 15% even after any maths errors)

Most places have everything relatively close in price so that the disparity between the cheapest and most expensive thing on the menu is about £5 at most. In general if I like someone enough to share a meal with them they are likely to be someone I'd happily gift £5 to. If you feel BIL has taken advantage you could just knock it off the budget you allocate to his next Christmas present if it matters that much to you.

In our circle we always just order whatever we want.
If it really bothers you this much though then just say something next time.

Everyone should order what they want - the person ordering the more expensive dish just chucks in an extra £5/£10 surely.
Imagine paying £15-£20 for somethina meal you don't really want to eat just because the rest of the group are watching the price of what you choose.....

Order what I want. I’d go for he mixed grill as I mainly eat meat. It makes you sound tight by saying this

I go out with a few different groups of friends and everyone always pays for what they have, maybe it's because we are all similar personalities and recognise that no one should have to feel they can't order what they want because it might cost someone else more than they can afford but it does lead to a bit of maths at the end of the night so I'm interested in how you get separate bills and still get the food to arrive all together. Is that now a standard thing ?

Then stop splitting the bill with him and all pay for what you have! Easy! You are making this harder on yourself.

Everywhere I have been has a mixed grill. It is a standard option.
I’d be disappointed to not see it on a menu to be honest.

I eat out with various groups quite regularly and we do generally just split the bill. If someone orders much more expensive items than the others (rare), they do sometimes offer to pay more, but it wouldn't bother me if they didn't, unless they did it every time.

When I eat out with colleagues (in a work situation, not as friends) we usually each pay for what we had, as some earn a lot less than others.