nightgowning
(v.) the act of hiking up one's leg garments in order to hide them under a longer than normal torso garment to provide one's peers with the appearance that you are not wearing said leg garments
Example:
When Jeph's jersey was hanging over his shorts he looked like he he had a nightgown on. He was actively nightgowning.
When Jeph's jersey was hanging over his shorts he looked like he he had a nightgown on. He was actively nightgowning.