Was That Bad Acting by Jon Hamm?

Watched the Mad Men premiere. The major moment of the episode was a surprise party that Don's new wife threw for him. And if you don't know, Don Draper is not the kind of guy who likes surprise parties.

Everyone from work was there (well, except for Joan and her whore child). In the middle of the party, Don's wife gave him his present, which was her seductively singing "Zou Bisou Bisou".

Now, besides the fact that that's kind of a bullshit present, the consequences of this performance reverberate throughout the rest of the episode. Don is pissed about it. They get in a big fight. People at work are uncomfortable. They talk about how mortified Don was. It was a big deal.

But here's my problem:

Don is enjoying himself! He seems to be turned on by it. He likes it. He smiles and kisses her at the end. He's not worrying about the other people there. He's not thinking about his coworkers. Everything seemed fine.

So was this bad acting by Jon Hamm? Am I misinterpreting everything?

Probably. But there's a possibility that this scene didn't play as they intended. While I was watching it, I was expecting Don to be angry. And then I thought, "man, are we gonna see a kindler, gentler Draper this season?" But then it changed, and everyone started talking about that moment like it happened the way I thought it was going to happen.

Maybe it's me. Or maybe Jon Hamm's been performing in too many comedy bits lately and was rusty.