I feel like we've entered chapter two of the Buddy saga (post-neutering recovery drama)...

Quick background: He is about one year old (the vet said), and we've had him for three weeks now (we found him as a stray...have no idea what his background is, though he was healthy when we found him, despite having tapeworms). Anyway, after the search for the owner (who never appeared), and deciding to keep him ourselves. We assumed he had been housebroken, because he never urinated once in the house and went to the door whenever it seemed he wanted to go outside. Everything seemed great.

THEN...

We had him neutered last Tuesday (ten days ago), as some of you may remember in some other posts of mine (he had a rough time recovering, due to infection). So last night, since his "housebreaking" track record seemed to be so good, it came as a surprise to us to find that he had urinated in the hallway, on the carpet (while one of us was here, no less...). We thought maybe it was a fluke, that maybe we had been busy when he had given us signs to need to go out. Today we took him to have his stitches taken out and he did great. We left him at home for a bit by himself afterwards, and took him out before we left to let him use the bathroom, which he did. We came back three hours later to find a lot of chewed up books, had urinated on a rug in the living room, and to find that he somehow managed to make it to the top of the table where we keep our cat's bowl of food and eaten it all!!! It was surprising, but we gave him the benefit of the doubt, thinking that maybe we had been gone too long and he was acting out because of it. So not even ten minutes ago, we were all hanging out in the office (me, my husband, Jasper the cat, Luke the greyhound, and Buddy), and then we hear him start peeing on the floor in here! He had JUST been outside to potty not even twenty minutes before that!!!

So, long story short, I'm looking for any advice that you all can offer...we don't crate him, because we thought that he had done so well on his own thus far that we wouldn't need to—we didn't crate Luke and he has always done great at home by himself...but now it is seeming that it might be our only solution! Has anyone else encountered anything like this? Would this be considered "submissive urination," because he and Jasper (who is a tough kitty who can hold his own against Buddy!) were just playing moments before this incident in the office?!

Apologies for the length...any words would be GREATLY appreciated!