She REFUSED to meet MIL. Originally she was going to bring SS to work with her tomorrow at 5:30 am - she goes past MIL's house but won't drop him off. MIL offered to meet halfway between work and MIL's house at 7- BM1 refused. MIL offered to come to her office at 8 am tomorrow (they need to be at the airport at 11 am) and BM1 has now refused that as well.
I guess MIL got pissed with all the back and forth texting, so she called BM1. She said "I don't trust you to get SS to the airport on time, and you are making it extremely difficult for me to pick him up. I think you're doing anything you can to ruin <Dh'> and Wendi's vacation. It is MY JOB to get SS to the airport, and if I have to go to your house and drag his @ss into the car, I will." So 2 hours ago, when SS was out of school, MIL was waiting at his house to bring him to hers. This poor 72 year old woman drove from one end of Iowa to the other picking up both kids today, so she would be sure they got on the plane in the morning (predicting snow).
For the record, SS is super excited, keeps calling DH and asking what he should bring/wear, etc. So it's not that he doesn't want to come, it's that BM1 is being a dramatic wh0re because she can't control the situation.