I'm taking it this way: the writers wanted to show like one perfect day when House was a normal guy and he was in love and it was all roses and unicorns. And from the next episode on it will be the 'real" world of House and the way he will screw it up and how he can't help being a jerk and even Cuddy won't put up with his crap. And so he'll move back in with Wilson and Sam will vanish and it will be okay.