Not at all. We're all just trying to maximize our own utilions. My utility function has a term int it for other people's happiness. Maybe it has a term for other people's utilions (I'm not sure about that one though). But when I say I want to maximize utility, I'm just maximizing one utility function: mine. Consideration for others is already factored in.

Thirded. I would add that my utility function need not have a term for your utility function in it's entirety. If you intrinsically like murdering small children, there's no positive term in my utility function for that. Not all of your values matter to me.