Unbeknownst to those not well acquainted with arcane knowledge. Days of celebrations can draw all sorts of extraplanar travelers to the material, some to relish in the celebrations and some to profit off of it. Many fey and devils get drawn to the Red Rose Celebration for all the same reasons. to profit off of the psychic energies of the masses, and to either create harmony or HAVOC.
Fey
The fey courts and markets barter trinkets of high emotional value as currency. So why not skim a few trinkets off the top when everyone is seemingly producing them by accident? Many gifts and trinkets tend to go missing during the festivities, due to all sorts of invisible little bastards like the Quiklings or Pixies. Quite a few marriages may even fall apart when the husband mysteriously loses his betrothal rings. It is even said that in some major cities, where it is customary to give the gift at night, that you can stand out in the street and listen out for the "slapping hour". the most harrowing time of night where people only just discover if their gifts have been robbed or replace with some other prank like product.
Devil
When emotions are high, people tend to do whatever it takes to get the best gift, or sell out some souls to ruin other's gifts or lives. All levels of the nine hells become busy with all manor of creatures willing to pay anything to get their perfect revenge or reward. Such contracts on this day seem to be very cheap even for humanoids, shying away from taking even a single soul. Little do the poor sinners know that this is exactly what some archdevils like Mephistopholes desire. The more summons done in one day in one area can weaken the planar divide, making it easier for other devils to slip through, and even begin plans to establish a functioning gate to some outer parts of the nine hells. All any competent devil needs is a few more sorry souls to wish to "get the girl" or "find the perfect gift". These devils will always provide a stellar service.
Blue mages
if we were to quantify the levels of bliss and stress that groups of people were to feel during these two days, the blue mages would be the top of both charts. For it is this day that everyone is scramble for the best love treats, medicines, aphrodisiacs, and services that money could buy. Shelves are pumped and emptied faster than whores in the slums. But any seasoned Blue mage knows that they are pulling triple duty when it comes to keeping the fey and devils at bay. Its hard to do business if you have sprites attempting to steal your goods away from your paying customers, or if your bordello suddenly has an incubus that you did not contract with. If left to their own devices, these two forces of horniness and chaos will either run your business out of town or into the ground. So on these days it is not so rare to see some Blue mages walking the streets with some hired help to try to keep the festivals fun and fairy free, lest they do bodacious battles with the most arousingly rampant ne'er do wells from all sides of the cosmology wheel