Use Her Naivety Against Her

You decided Riley is trusting enough to believe even the most ridiculous lie.

"Well Riley, the biggest issue i see is your yoga pants."

"Whats wrong with them?" She asked innocently.

"Yoga pants always get in the way of full stretching of the muscles. Ot would be best if you did the rest of your regular stretching without them."

Riley seems hesitant at first but eventually decides you know best. Gathering all her courage she slowly removes her pants and begins her usual yoga routine.

"See isnt that better Riley. Your form is looking better already"

"Wow really. Thanks mister. I really appreciate the advice.