FI's birthday is coming up, and when I was trying to plan something to celebrate I suggested going to the shooting range. I was thinking just the two of us, but he said it would be great if his best friend and his wife and his other friend (and presumably other friend's girlfriend) could come. I was expecting to pay for the two of us and hadn't budgeted for paying the range fee, plus gun rentals, eye and ear protection, ammo, etc. for six people.
I know that guests shouldn't be expected to pay for anything at a hosted event like a dinner, but I'm not sure if this is considered a hosted event? I was thinking of sending out a casual message via facebook to say, "FI and I are going to the shooting range for his birthday next Saturday, and I know he'd love it if you could join us." Would this be considered a hosted event? If you got an invite like this, would you assume that the person who invited you was picking up the tab?