An interesting idea that could be added later on would be coloured bracelets for the prudeworlders.
Like different colours for different status. Like green for "use at will", yellow for "ask first", red for "not interested" and maybe a special one like purple or something for "exclusive" for those who want stay loyal to their lover. This could fit into the story fairly easily as an attempt to promote cultural integration/acceptance at the university. Be it as a program that already existed that the mc forgot about in his rush to get into the free use world or a new program.