If the interest is specifically in the terminology, an essay could examine how the adult industry uses highly specific descriptors (like "double") to market content through search engine optimization (SEO) and how that influences how gay men perceive their own bodies and sexualities.
How magazines and early gay cinema popularized this specific look. gay twink double
You could write about the history of "tribes" in the gay community (e.g., bears, twinks, otters). If the interest is specifically in the terminology,
The pressure within the community to maintain a youthful appearance. 2. Doubling and "Boyfriend Twins" gay twink double
Creating a sense of belonging and making it easier to find like-minded partners.