Way of the seven sighs
When Daenerys Targaryen informs her councillors that the Wise Masters have assembled a slave army to face her army, Grey Worm dismisses it by telling her that Yunkish slaves are trained in the way of the seven sighs and the sixteen seats of pleasure, whereas the Unsullied learn the way of the three spears.
After Daenerys takes over Meereen and her freedmen take residence in the city, a number of brothels sprout throughout the city. Daenerys remembers that half her freedmen hail from Yunkai, where they were trained in the way of the seven sighs.
When meeting with Haldon Halfmaester and Hugor Hill at Selhorys, Qavo Nogarys reports that a Yunkish envoy arrived at Volantis with chests of gold and gems and two hundred slaves, nubile girls and smooth-skinned boys trained in the way of the seven sighs to bribe the Triarchs.