Fyrexai (meaning Soulmeeting in Vhessan language, commonly summed up as Meetings) are a very central and important part of Vhessan culture due to its strict division between both sexes (that can be seen and felt even in city planning and general architecture. They occur on a daily basis, with a lot of it being pretty much equal to sex without commitment that sometimes borders with an orgy (not to mention plain old prostitution).
In the ancient times before the Xylian Dominion demise in Black Iron War, dark elves were an object of prolonged program of selective breeding at the hands of the Xyls. The careful process of selecting future mates by xylian genmaturgists remained to this day, in a form of fyrexai. It mostly devolved, today being nothing more than a faint remainder of what it once was. Noone besides the Twice Seven remembers the origin of Meetings anymore.
Meetings takes form of a meeting between members of opposite sex of both species that inhabit the Vhessan Empire, and in fact most other countries of dark elves. They happen at certain buildings built on the intersection of districts housing unmarried males and females. They can be described as places of pretty much perpetual dates. Males and females go there when they please, wearing masks that are marked in a way to signify their caste. To meet members of opposite sex, and talk. Drink alcohol. Be merry. Many of those buildings are in fact places of unrivalled debauchery. Including drugs, sex that sometimes borders on orgies... not to mention political intrigues. Officially this doesn't happen, unofficially pretty much everyone knows of a 'friend' that attends it and can direct newly arrived person to a buildings that.. cater to their tastes. The debaucherous approach to fyrexai happens mostly to the young adults. Sooner or later (in most cases while being around 30-35 years old) they end up searching husbands and wifes for real. They are fyrexai houses dedicated to it as well. After meeting people they decide they like and feel good with, they marry. Making it at least partially a courting ritual.