As a college graduation gift, my mom and I are going on a cruise. My dad and sister will not be be invited to go. My sister isn't going because she will get a gift as well when she graduates. There are a few reason why we aren't bringing my dad with.

1. We would need to get two cabins instead of one 
2. It's a lot easier to coordinate what we are going to do and when since there would only be two of us
3. Having my dad with us can be kind of stressful. I love him, but our personalities clash and it's easy to set him off, so there is ALWAYS a fight when we go on vacation
4. I want to spend time with my mom because I don't get to spend a lot of time with her since her working hours are so long

When my mom told him, he was pretty disappointed. I feel really bad about it, but I also don't want to change it so he would be going with (the cruise is still a year away). It's not a regular thing where he gets left behind (I can only remember one other time where he didn't come with us and it was because he was doing his own trip somewhere).

AITA for leaving my dad out for this vacation?