Update - Graduation
So their "Daddee Daughter" trip, as well as the graduation, has come and gone. DuH sent non stop photos of SD sunning herself on the beach and the two of them posed in front of every tourist attractions. I deleted them all. When he called the one time while on said vacation, I faked being happy to hear from him and had my toddler talk to him. We were on the way to daycare/work for me, so I had to get off rather quickly (2-3 minutes). DH felt I did not demontrate the appropriate amount of enthusiasm, and proceeded to turn off his phone the rest of vacation so that I couldn't get a hold of him. Then asked me what time I would be picking up him and SD from the airport. I informed him we had plans that day and that he would need to take a cab. SMH.
Graduation at the winery was strained. BIL and SIL were cold and distant. I said a friendly hello and found a seat at the other end of the table. No love lost there. DH did invite everyone back to our home after. I decided not to argue on that one - I was too tired and just told him to make sure everyone was out by 9pm. He did, no drama. My mother did end up coming to help with the LOs. MIL made a comment about how great a father DH is... and unfortunately, dear old Mom responded with "Sure, when he has an audience!". MIL gave daggers eyes to Mom, Mom turned about three shades of red. They talked later - and my Mom apologized, and expressed how disappointed she was to see how little DH does around home or interacts with the kids. MIL admitted that her husband (DH's Dad) was the same and so she isn't surprised.
But the real update has to do with SD. She finally showed her you-know-what and it became clear to DH how much he's been used for money and vacations. They had a blow out fight that lasted the span of two days, and was rude to me. She is back with her mother now. I have not seen DH cry like that in a long time. Of the many things he said - "you were right, she's a user, she lies, and she's nice only when she wants something". When he proceeded with "how did she get that way?" my head nearly exploded. He really doesn't see his role in all of this, and will most likely revert when she comes tearfully crawling back.... right before she asks for more money or whatever else she needs."
She leaves for a summer program in a week. Comes back for two weeks in August, and then leaves for college. To say that I'm relieved is an understatement. We are moving the kids rooms around when she leaves in the Fall. He new room will have the shared bathroom, and I'm really looking forward to painting, and making it look like an actual guest room. I will always welcome SD for a visit, but I already stated to DH (after he stopped crying) that next summer, her moving home for an entire summer is not an option - and if he attempts it, I will be moving out. He didn't argue, and said that was probably for the best.