[Symmetry]

That's actually a fairly neat question for sifting different types of Utilitarians. Do you care about other people's happiness, or about their utility as they define it? In B you're really screwing over one of the couples, but they won't be around to be unhappy about it.

[dedward]

you are part of the equation, no?

[Symmetry]

Yes, but unless they have a very strong attachment to one or both of the couples our hypothetical utilitarian judge is going to be a very small part of the equation. For the record, I'm not a pure utilitarian myself.

[dedward]

the question indicates you do care about them, specifically.