Hey there,

Facebook ad targeting options are always changing, so it's possible that they've removed that Behavior option for a variety of lessons.

The easiest way to substitute this functionality would be to use Interests instead of Behaviors, and go after fans of Big & Tall, Casual Male XL, and other similar retail stores.

If it's helpful, we've put together a complete guide on every Facebook Ad Targeting option currently available at http://www.contentharmony.com/blog/facebook-ad-targeting/ . This page is easier to search than hunting through the entire Facebook ad interface.

Good luck!