“I like dogs fine” Dean shoots back with a wounded pout, as if Sam's suggested that he's a horrible person who runs around kicking them or something, which fractures into another grin as he continues “I put up with you, don't I? That's kinda the same thing.” The cheese sauce is pretty damn near perfect now – Iron Chef Cora (aka 'the future Mrs. Dean Winchester' – for as long as he's got access to Food Network, anyway, and whenever Lea's out of earshot) would be proud. “Except that you know better than to shed on the upholstery or chew my shoes...”
He's pondering the advantages, such as they are, of having a Sam rather than a Dog when the knock comes, and being the manly hunter he is it's not a jump, it's, um, years of combat training, which he's quick to push away so he doesn't startle Sam because Sam still actually jumps, settling on an 'It's fine, I'll handle this' sort-of thing as he moves the pot to one of the other rings (because damned if whatever totally non-threatening innocent visitor is on the other side of the door will make him burn his perfect sauce) and heads over and opens the door to be confronted with...
“... what the...?”
There's various things he's expecting in various degrees of 'don't think about that', but an angry pre-teen armed with a shovel isn't one of them, and he stares at her sidelong for a moment or two before shouting back into the apartment “Sammy? What'd you order a midget for?”