Ah, well, don't worry too much about where the money came from, and the fact that he complains about being broke. It's nice that they had a good time together.
I think a lot of non-custodial parents feel the need to do something "fun" when they see the kids. My kids lived with their dad most of the time, and so they didn't really have a regular "routine" when they came over. So I usually had at least one "fun" activity or outing planned.
I think you are doing great.