demanding FFIL (kind of long)

saisongbird

You need to be careful.  I know that you're trying to please your FFIL but you and your FI need to stand up for yourself here.  You have to set this boundary or your FFIL will try to take advantage of your for the rest of your lives together.  Please don't take this the wrong way, but you sound like a bit of a pushover, and my gut is just telling me that if you don't take a harder line with FFIL, you're going to be stuck paying for the rooms.  Having a backbone is not a bad thing!

marinabreeze

I agree with PPs, and I second saisonbird's sentiment.  FI especially needs to stand up to his father.  If you, FI and your parents are footing the bill for the wedding, he can't demand things that he doesn't pay for up front.  That simple.  He can't *make* you do anything.  FFIL should not be able to push you and FI around.  Again, FI needs to stand up to his father.

While I understand what aMrs. is saying in terms of taking control of what information goes out to guests, my concern would be that by putting his note in with your invites, that his OOT guests will count on his offer of help when they RSVP and plan to come to the wedding.  If he reneges on his offer, because it was in your invites, it would reflect badly on you and FI not to have covered their rooms after it mentioned in the invites that their rooms are covered (not because you offered, but because it was included in the invites as if it were a sure thing). 

I have a feeling he's going to leave you guys on the hook for this.  So  I would also say to go with squirrly on what to do.   Make sure you have the money (check cashed and cleared) up front before extending to his guests his offer, and then give him back the difference when his people accept or decline his offer.  Present that as the only option, and if he says no, then don't include the offer and continue on as previously planned. 

Realistically, FFIL could run and tell people on his own that you'll cover their lodging, but unless it comes from your invites and/or communication you or FI have with said guests, you're not on the hook for it.  And if they ask, let the know politely that there is a misunderstanding, and you cannot cover their lodging, but a block of rooms are available at XX hotel(s) at discounted rates, and you hope they will still be able to make it.  Then it will reflect on *crazy* FFiL, not on you.

MyNameIsNot

I have to disagree with PPs.  

My parents are not BSC, but they did cover hotel rooms for some people that came to our wedding.  It was completely separate from the invitations.  My dad called his brother, said hey, so you can't stay with us that weekend, but we'll pick up your hotel room.  Dad booked the room, and we never had anything to do with it.  

I say let him handle it.  Give him the booking info for the hotel block, and tell him he can book whatever rooms that he wants to cover.  He can get RSVPs for the rooms and book them himself.  If he goes around telling people you are covering rooms, he's the one who looks like an azz when you politely explain that you have no idea what people are talking about, and that FFIL must have been offering to cover the rooms himself.  

I see the appeal behind asking for the money upfront, but I just don't see the point of taking control over this issue.  If he offers, he offers.  He can't make an offer on your behalf, and if he offers and falls through, it only looks bad on him.