House thoughts post "Joy"
So... House was possibly more of a bastard than usual this week. (The fact that I kept yelling, "House, stop being an asshole" at the screen was my first hint.) And yet, I'm kind of happy about it after the fact because it feeds into one of my pet theories.
House always expects that he's going to be ditched by the people he cares about as soon as something better comes along or the going gets too rough, hence his attraction to damaged souls (less likely to find something better). And, if he's going to be ditched, he wants to be rejected on his own terms. Thus, when something potentially better does come along-- Amber, Joy, etc. -- House becomes a bigger jerk than usual. He does the same thing when circumstances spiral out of his control (Amber again, the Tritter mess). That way, when his friends dump him, it's because he drove them away, not because they just decided on their own that they could do better. It's that whole trust/control/whatever thing that he has so much trouble with.
I think it ties into the paternity issue -- I'm sure that House always suspected that a big part of the reason his relationship with John was so strained was because John knew that he wasn't the biological father. This might actually be the root of this particular issue of House's -- if he felt that he spent his whole childhood being punished for something he had no control over, he might feel the need to have that sort of messed up control over other people's reactions to him. Meanwhile, who knows if John was really harder on Greg because of the paternity issue (it could have been strictly out of spite, but it could also have been a subconscious effort to "claim" Greg as his by making him conform to John's standards). Also, John could have just been a hardass who would have been just as big a jerk to his biological kid. There's no way of knowing what his motives were now, and while knowing might have made a difference 40 years ago, it wouldn't anymore . Like House said after he got the results back, it doesn't change anything.
And now I'm totally rambling. Bottom line: the way House turned on Cuddy in this episode fits my theory. This doesn't make House less of a jerk for doing it. It does make me feel sorrier for them both.