Keep her mind foggy

As you probe the teachers mind, you find it quite easy to throw away anything other than the importance of Yoga, being completely in the moment, not noticing about her leggings.

The rest of the group watch in shock as the leggings rest at her knees, and she shows no surprise or embarrassment.

"Now into Warrior Two," the teacher says, suddenly lunging forwards.

Under ordinary circumstances this would clearly bring her predicament to her attention. However you have the slight control over reality. A simple gesture and the leggings completely split at the gusset, allowing the teacher to lunge forward into Warrior pose, the leggings just gathering around her ankles, as the wide eyed students watch in surprise.