Blimey, this thread got a bit out of hand last night, didn't it! 
Hope you had a good read, Solost - The Goblet of Fire is currently DS's favourite film, despite him being 3.2, because it has dragons in it. So every other day I get asked for "Harry Potter dragons, mummy?" I'm sure I'm a Bad Parent for letting him watch it at such a young age but he doesn't seem to have had any ill effects so far...
Glad you had a good laugh on here anyway - it's always nice to get a bit of light relief!
NOw for some hard stuff - so your H has to look after DS and DD2 on Sunday, picking them up from your ILs and bringing them back to the house. Is there some way you can limit his familiarity with the home? Perhaps change the kitchen drawers around or something? I would also consider locking your bedroom door if you have that facility - none of his business what is in there any more.
In fact, is any of his stuff left in the bedroom or elsewhere at all? If so - go and bag/box it up, label it clearly and tell him in no uncertain terms that either he takes it with him on Sunday when he leaves or you will dump it.
He needs to realise that your home is no longer his - so oust him from it.