I have not delt with this personally, but I can tell you what i have read on the issue....this happens often and comes from a mix of emotions. Guilt, Fear, and sadness. Dad's probably feeling a heavy dose of all of these things right now, Guilt that he won't be around for his kids this summer, Fear that they might go to BM's and never want to come back, and Sadness that they're leaving! I'm sure these are really hard to handle as a SM, they aren't our kids right?! So there really aren't any emotions like that for us,(Maybe a little excitement though at having the place all to yourselves and no kids!) So maybe Dad needs to be cut a little slack, or maybe he needs to get over it and shape up. What do I know, but I'll bet for all the crappy moods you put up with until they leave, he'll find ways to make up for it! OR you'd better make him!