Compostable Kate

I'm looking after Mack again for a few days.  I first looked after him when he was about 6 months old, and he just about got the better of me then.  He peed on every last mat, rug or bed - multiple times - including his own.  He would do it just after he'd weed outside.  To me, it seemed deliberate.  He'd wait until I took my eye off him, and then pee on Dexter's bed (again).  I've never done so much laundry in such a short time, or been so angry with a dog.  Six months on, he hasn't peed on anything at all inside, although I still watch him with some suspicion when he's sniffing about.  However, he's replaced peeing on Dexter's things to humping Dexter, or if not humping, stealing his toys.  When he leaves Dexter alone, it's usually only to bother the cat.  Mack seems to think this is the best fun he's ever had.  Dexter, on the other hand, has become quite aggressive towards Mack, especially over toys.  Mr D's had to have his time-outs