M2's party is Sunday. MIL is always annoyingly early (like an hour). BIL always bails at the last minute. He replied him, wife, and 3 (teenagish) kids will be there. I'm taking bets on what time MIL will arrive and how many of BIL's family actually shows.
I'm guessing MIL will be here at 11:30 since I aske my mom to come at noon to help with last minute set up and because she's bringing the cake.
I'm guessing at least 2 people from BIL's clan will bail- the wife and the 16 yo. That's ok because they are both annoying.