Although he agrees that Rose very much deserves, and needs, to be a part of this discussion, her presence literally right in the middle of things, complicates matters by at least a factor of ten. Probably more. Assuming he's the only one here with anything resembling common sense, he takes it on himself to get thing under control. He murmurs his thanks to Jack and gives his hand a squeeze so it's doesn't seem like he's giving Jack the brush-off, then takes another step forward.
"Lady and gentlemen," and I use the terms loosely, he thinks to himself, "as much as I'm sure we'd all love to continue this lively and spirited discussion, this is not the time or the place. Far too public." And attention getting, what with the raised voices and the identical Doctors with their identical TARDISes. "Why don't take this inside, sit down, I'll make us some coffee, and we'll discuss things like the rational beings I'm sure we all are." Somewhere deep down.