My aunt is asking for my help to book my grandma's flight to Bacolod because my grandma's sibling passed away, and they took my dad (grandma's son) along to help her.

Now, they want me to pay for my dad's return flight, and since it's an unexpected expense and I have a lot of other bills, I don't want to pay for it because they were the ones who took him, so they should pay for it. I have many other things to pay for.

Another one of grandma's children (my dad's sibling) and their spouse are also going, but their flight is a day before grandma's. I'm wondering why they didn't travel together and why they aren't the ones taking care of grandma if they can't afford my dad's flight ticket.

Any advice?