Tobirama comes down to breakfast on the first day of classes to find the Great Hall full of snickering, his husband conspicuously absent, and his brother face-down in his eggs.

“Reborn!” He squeaks, voice caught somewhere in his throat as panic starts to set in. Coming to the swift and horrible conclusion of what his sadist tutor is going to make him do. His thoughts are proven right as Reborn begins to explain. “When searching, people tend to overlook the opposite sex. No one thinks a mafia boss will be willing to put on a dress just to escape from capture. They assume it is against their masculine pride or some such nonsense.” Reborn’s grin is practically predatory, obviously enjoying Tsuna’s discomfort. “That is why it always works if you know how to blend in correctly.” ----- aka; the fic where Tsuna goes undercover as a girl to a local festival to learn how to avoid being captured by enemies, but ends up sexually frustrating Yamamoto Takeshi who wasn't aware he had a very specific fetish.