I eat out regularly with 2 separate groups of friends.We are fortunate to have lovely pub meals around here in Derbyshire costing between £5 & £7
In the 1st group we each go to the bar and order / pay for own. No problem
The other group is mainly elderly and infirm ladies and they are hilarious. We inform the landlord before hand and negotiate a set price of £10 with them for a 2 course meal with 2 choices, There's usually more than 10 of us and for many of the ladies, this is their only monthly outing. It is always the same car drivers who go around picking up those without transport but you do have to watch out because especially the portly ones like to swing on the car door when getting in or getting out of the car. There is never any question of offering to share the cost of fuel. They must think cars run on fresh air.
These outings are hilarious. Some of the ladies forget what they have ordered between the final order being given to the waitress and it arriving. They chunter with each other that they haven't got what they ordered and point out who it is that is eating their meal - probably because the other choice looks more tasty than the one they have got. Some of them bring a plastic bag with them to take what is left home for their tea.
On one occasion, 1 lady went home in a coat that must have been 2 sizes too big and when the other one went for her coat , the buttons wouldn't fasten! The 1st lady had left and we didn't have her address with us.
We have got around the 'tip' scenario by adding £1 to each person's bill - so no falling out there.
Drinks are a different matter, we always have jugs of water on the table and anything else has to be paid for separately.
Reading this it may sound like a nightmare but it isn't and if we didn't do it some of these ladies would be completely housebound.
I could see them falling out if one person had to pay more than £1.50 than the others.