Thor moves with the strike, laughing, so she doesn't accidentally hurt herself throwing herself headfirst into six hundred pounds of Asgardian warrior. He feigns a stumble but stays on his feet, carefully tossing her away so she'll land on her feet, even if she has to flutter a bit to do it. He can't make it too obvious he's taking it easy on her.

He stays facing her, as if confronting the most deadly of beasts, circling to keep her in front of him. This Princess certainly has spirit, he'll give her that; worthy of a warrior of Asgard.

She's far more delicate that he is though, obviously, so he has to be extremely cautious when he makes as if to strike back at her, having to deliberately misjudge the distance as she bobs and scurries out of the way of his hands.