my niece and nephew certainly don't expect payment, nor does my sister, i am giving them money probably more as a thankyou.
I am paying it probably because i didn't really think much about it... and Ex wouldn't have thought to do it, only reason he knows is because i told him that on friday when he picks up their stuff there would be a bag of munchies plus cash to give to them.
He probably could pay but *shrugs* we are still good friends so it isn't bothering me that it comes from my pocket, he is good with things such as child support and providing extra money for things if they come up.
As for him missing this festival, i wouldn't even ask him to do it... neither of us have been to one before and it has a massive line up with so many of our favorite bands that I was happy when he was able to get a ticket after they sold out. I would have hated him to miss it as it is going to be an awesome day