A Fox in Disguise
Yes, your eyes are not deceiving you. That is a foxtail coming out of his pants. Attaching a fake foxtail from jeans is definitely a confusing choice of a fashion accessory, but it sure is unique and would certainly help him in breaking the ice with anyone he wants.
Source: Twitter
One possible explanation for this foxtail could be that the Halloween season was in full swing, and he was probably there looking for a full fox costume. Or he was procrastinating in detaching the tail from his pants after last night’s party. Whatever the case may be, the tail does baffle a person at first sight, and perhaps that is what the person was aiming to achieve.