BP Party drop out 2 months before the wedding

So, one of FH's GM's calls today and tells him he won't be able to come to the wedding because his wife scheduled a lecture the day before the wedding in Texas. This guy and FH have been friends since they were like 5 years old and he introduced me to FH; so he's an important part of our lives.

FH is really bummed about it, so is his friend but I can't help feeling a little resentment towards his wife for scheduling this when they knew the wedding was on April 24th. I mean, I thought we all got along fine and this is an important day for FH and his friend wanted to be apart of this day. But now he needs to go with his wife to Texas; he has no choice because they have a child and he would have to take care of the baby while his wife is giving her lecture. I feel really bad for FH, he was not himself today after speaking to his friend.