He leans over to Rose's ear and whispers (a bit loudly), "Flexible dancing, remember?"
The Doctor shrugs. "Maybe. One life and all that. I mean, we're bonded already, so might as well follow Earth standard too." He realizes that sounds a bit lackluster, which is not how he feels at all, and explaining the bonding gets tricky, "I love her, Jack. So why shouldn't I make it official?" He grins again.
"Wait, you're MARRIED? I missed a wedding? Oh, you're invited to ours, now, of course. And of course I'm happy for you!" He reaches out and pinches Jack's cheek. "You're just so grown up now!" He winks.