DCs are getting christened on Sunday. They're having 4 godparents between the 3 of them (some are doubling-up). The christening was organised last-minute as DH's grandma, who is very frail, said she wanted to see the DCs christened (we were always going to do it but it has become urgent due to her health). The vicar made a big effort to get us this slot and the godparents were all free so we decided to go ahead. The godparents are doing us a favour - rearranging their weekends and stuff - to be gps. Wanted to show our thanks.
Booked a nice local restaurant for lunch for the 10 of us (including the 3 DCs so 7 adults eating/drinking - more like 6 as DH's gm doesn't really eat anymore 
).
We have a very strained relationship with both sets of parents, neither of whom are religious at all (MIL was very uncomfortable with us having a church wedding and she and FIL are hardline atheists). But DH's grandmother told the ILs and they said they wanted to come, as does BIL. BIL (who has learning disabilities), was hurt he hadn't been asked to be a godfather so we added him. So now that's 13 of us.
Knew at that point my parents would be very VERY hurt if we didn't at least invite them, so we let them know it was happening and very low-key, etc. Of course they would come, and they made a big fuss about how much they'd rearranged to do so (my mum feels competitive towards MIL). So now there's 15. That was last week.
Just now, my sister texted my DH to tell him that she and BIL have booked flights to come as well! We'd already let them know about it and they'd said they couldn't come because they had a friend's wedding in a city miles and miles away but they're leaving v early Sunday to be with us.
So now there's 17.
The ILs and my parents and sis/BIL are all heavy drinkers. Nobody will be falling down drunk but FIL will have five or six beers (as will BIL), my mum and MIL will have a bottle and a half each at least, my sis and BIL are also chuggers.
On FIL's last birthday, big meal in a major city, MIL was ordering LPR left right and centre. She couldn't pay the bill and DH had to help out.
If we'd known there would be so many of us we'd've booked somewhere else (cheaper), but we've rung round and there's nowhere who can fit us in at this stage - original venue has a lovely outside area they've reserved etc. Also DH's grandma REALLY looking forward to going to this particular place and has said so multiple times.
They can increase the number from 10 to 17 but only if we all order by 12.30 etc etc. Stress stress stress.
I rang and asked for wine to be ready for our arrival (the cheapest ones), to stop someone ordering champagne or something but the cheapest wines are £16/17 a bottle. The original 6 of us are all small eaters but if people order starters and main courses it could be £30 a person for food alone, maybe £50 including drinks.
DH and I really can't afford that. The meal for 10 of us would've been a stretch (we've also ordered a cake), but we weren't worried - nobody we invited is a big drinker, nobody would've taken the piss by ordering the £21 rib roast (what I bet my BIL and FIL and dad will do at least).
Now, I was always raised to believe that if you host an event like that, you pay. Would not DREAM of asking the godparents to stump up. DH wants to 'let people know' (his and my families), that we'd like donations but I can just see that turning nasty and making people feel uncomfortable.
I'm voting for grin and bear it but it's made us massively stressed. Nobody in our familes really 'understands' (cf LPR and last-minute flights across the country); my parents, sis and BIL v affluent and the ILs are extravagant.
Don't want to marr the day for grandmother-in-law but it's all a massive stress now. But I do think that we should pay (or at least be 100% prepared to), since it's our event.
AIBU?