The Voyeur's Wand was made by a student at a magical academy who was known unofficially to the other students as Squirmtongue. He had no friends and girls laughed at his attempts to date them, and he developed a hidden hatred of loving couples. One term he smuggled one of his own wands into the school, a serious offence involving suspension at the very least if he were caught.
Students were issued with a wand each by their masters, and bringing their own wand was prohibited for two reasons. First, wands could be used as weapons and were potentially as dangerous as crossbows or swords. The masters did not want someone to be hit in the back with a fireball or worse. Whilst fights rarely happened at magical academies, there were a few historical examples that had ended very badly indeed for the loser when wild magic was involved. Also, unauthorized wands could be used to cheat in exams or to do stupid pranks with. At the end of each day, student's wands were checked by a master with a simple cantrip that made them glow red if forbidden magic was detected, and then locked away in an iron safe for the night.
Secretly, using small amounts of magical powders purloined from the academy's magical laboratory he worked on the wand, sawing it down in the process, which made it an illegal item in itself. Whilst it was perfectly legal for an accredited wizard to carry a wand if he had filled in the right paperwork with the city guards, "sawn-off" wands had been banned for centuries, because they could easily be carried by criminals and used for evil ends. A legally owned wand had to be at least two feet long or longer to make it hard to conceal, whilst his wand was a few inches long. If caught, city guards and judges would take an even dimmer view of it then if it had been a pocket crossbow, shuriken or some other illegal weapon, as it was so dangerous.
He cast a spell on this wand that made it capable of making people have orgasms, be they male or female, and as well as using it on himself for his own fun, he secretly cast it's spell on other students and even staff, making them suddenly have an orgasm at the worst possible time, such as in assembly, in front of their friends or in alchemy class when they were making their potions. At least once someone knocked his caldron over somebody else as a result of this, who not only got scalded badly but had horns grow out of the side of his leg that needed expensive magical healing coupled with water from the Sorcery Springs Geyser Basin to fix. He found when he used it on others that he felt the same effect but he had trained himself to avoid the effect it had on him to an extent so he would not be uncovered as the perpetrator.
Eventually he used it once too often and was caught. Maybe someone found him out and informed on him, or he just got careless. He was arrested by the city guards, publicly expelled from the academy in front of all the students and staff, with his official wand broken over the Headmaster's knee in front of him, thrown into the city jail, and after a trial in which he was convicted, he was fitted with a Convict Collar , locked up for twenty years in a maximum security prison, and banned for life as a convicted felon from owning or carrying wands or weapons. The wand was supposed to be burned but someone stole it.
If a PC who has not trained with this wand first to resist it's effects uses it on something or something else, he or she can choose how strong the effect is but will suffer the same effect. An animal such as a wolf or a giant spider will be put off attacking by the effects, although it might later follow the PCs looking for a sexual fix. A human or a lesser Undead such as a zombie will continue attacking but will find it a lot harder to concentrate on fighting with a huge hard-on, allthough unless the PC has trained to resist the effects he or she will be as affected just as much. If it's something like a Lich, a demon or an Ironbonesor an Urn Beast , then it will have no effect on the attacker, whilst monks and other clerics have a good chance of resisting it's power.