Don't get me wrong. DrewP will be thinking of himself. If they have fun and forget about what is happening with their mothers, he won't have to see long faces or listen to whining. And he will also cement the relationship between himself and the kids and will have even more loyalty from them. Just in case there is something they may know that he doesn't want them to tell.
That is exactly what he is trying to do. When I was going through divorce with my ex of 20 years, he fought me for custody of our two daughters. While I was working full-time and going to school to keep a roof over our heads and feed us, he worked for "himself", with a very flexible schedule. He coddled the girls, setting himself up to be the "cool dad", taking them places, playing, having a good time. After our divorce, he even drove the hour and 1/2 to our home on one daughter's 16th birthday and showed up at lunch time at the high school to make a big "show" of delivering a dozen red roses to her. He constantly made these elaborate shows of affection and made sure everyone saw it. Of course, the girls' friends were impressed and constantly told them what a "cool dad" they had.
Little did they know about what he really did behind the scenes. However, now my daughters are grown and they now see a side of him they never saw growing up. My eldest daughter felt sorry for him, because he is always broke and so she bought him a cell phone and pays his bill every month. Two months ago, she got his bill - for $700 - which she had to pay since it's in her name.
As for the other daughter, he wrote her a check for $350, to "help her out", knowing full well that there were no funds in his account. She paid a bill with the money, and when it bounced, she was left holding the bag, so to speak.
So, now he is taking advantage of his daughters.
Similarly, DP's kids will see the truth in time. However, that revelation will be a bitter pill for them to swallow and will likely leave them emotionally damaged, even further than they already have been.