Dionysus, always wanting to be as helpful as possible, places one hand on Grantaire's butt and the other on his thigh, and gently nudges until Grantaire's hips sort of roll into the correct position. "There. So, imagine you've got a line from your hips straight up to your ribcage. Straighten your left knee -- try not to let your ribcage move though -- straighten your knee and as you do that it should push that hip up, like it's going to join with your ribs. Then bend that knee again to lower the hip back down."