...Well, tact would at least suggest that you not say it to them.
I understand that some of it can't be put easily into an analogy, because these aren't just "other people"; they're your subjects, and so there's a level upon which you have a duty to them. The house example doesn't account for that, nor does it consider the feeling that you personally have an obligation to put your happiness second to that of the people who depend on you.
But I still think they're distinguishable considerations. It's not wrong to be happy that something in your life is better, in and of itself. I think that's different than being happy that something in your life is better at someone else's expense.
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I understand that some of it can't be put easily into an analogy, because these aren't just "other people"; they're your subjects, and so there's a level upon which you have a duty to them. The house example doesn't account for that, nor does it consider the feeling that you personally have an obligation to put your happiness second to that of the people who depend on you.
But I still think they're distinguishable considerations. It's not wrong to be happy that something in your life is better, in and of itself. I think that's different than being happy that something in your life is better at someone else's expense.