Have I Mentioned I Am Heterosexual Today?/Sandbox

In order to establish and maintain their sexual preferences, some characters will have a lot of dialogue on how they are straight and their relationship with another character is purely platonic. No that there's anything wrong with it being otherwise but it is not so.

Note, this is not about turning someone straight or just taking a hardline on Ship Tease, but a constant affirmation of heterosexuality.

Of course, there is another side to this. If one doth protest too much via Suspiciously Specific Denial, many people will interpret as there being something there. And like all tropes, people will invoke this on purpose. If a character is obviously gay but makes a point of saying how straight they are, it's Transparent Closet.

Have I Mentioned I Am Heterosexual Today? is a trope that generally takes place in a work filled to the brim with Ho Yay or where Everyone Is Gay. If they're not just trying to convince people which way they swing but that they swing at all, it's Have I Mentioned I Am Sexually Active Today?. Opposite Trope to Have I Mentioned I Am Gay?. If a character achieves this through acting gay, that is Gay Bravado.