Nudity is also not inherently sexual. You can be naked for reasons outside of having sex, such as cleaning yourself, using the bathroom, changing outfits, sunbathing, relaxing, etc. None of those are inherently sexual.
Wearing drag is not sexual either. It's been a thing for centuries, and that's just the easily identifiable stuff.
Wearing kink gear is not inherently sexual, though I can understand that you don't recognize that because it has connotations. But you can wear it without it being a sexual act.
"Expressing" sexuality is purposefully vague. Is kissing expressing sexuality? Is holding hands? Children do those. That would be an expression of your sexual orientation. You aren't really making any sense.
That guy is the worst fucking developer I've ever known.