Judging from the way Peter's legs begin to immediately fold beneath him, it looks like he's about to collapse to the ground just like he did the last time he attempted to stand up.

This time, he doesn't. Not completely. One leg bent lower, one leg bent higher, Peter's standing at only 2/3rds his height.

But he's still standing.

Judging from the expression on Peter's face, though, he's having a hard time holding even that.