housemate issues

our housemate has taken to a childish sort of revenge against us. I can sympathize with him to a certain degree but right now I'm not feeling sympathetic.

He hasn't been in a relationship for a LONG time or had any prospects and he is now having to deal with us in a relationship everyday in his face. Also he doesn't like indoor pets. I have Jerry. But the flip side is that Andrew and I are usually playing elsewhere on the weekends and having dinner with housemate on weeknights and not being exclusive or disrespectful. We include him in hiking and climbing and sea kayaking adventures and nights out on the town which he never turns down. He always wants to tag along.

As far as Jerry is concerned: I clean up after Jerry constantly. He doesn't bark. He isn't allowed on the couches or the beds. And really, who doesn't love Jerry?

But housemate has obviously taken issue with the situation. On Saturday morning we woke to blaring horrible irish music because he apparently wanted to listen to music while he sat outside talking on the phone. The speakers are literally about 2 feet from our bedroom door and it was obvious that we were home. No apology from him, no comment about the music or the volume or pretending like he thought we were gone. He seemed very pleased, in fact.

Last night he pretty much told Andrew that he could do Andrew's job and he would never hire an architect. He knows AutoCAD; he would just design his house himself (read it with an appropriate amount of bitter sarcasm, please)

It seems as though housemate knows how to piss us off so he is taking advantage of that. But I would like to know what his issue is with us. I would like to know how to fix it. But his approach makes me want to respond in an equally childish manner and pour a can of tuna fish into his bed. but maybe he likes tuna fish, we'll have to have a talk.