In Fable 3 for the Xbox 360, there is an ability for some weapons that will only unlock by having an orgy with four other villagers.
The easiest way to do this is by visiting the Brothel, because other villagers will only have sex with you by holding their hand and leading them to a bed, while whores will follow you without holding hands after doing a “sex invite”.
When visiting the Brothel, simply go up to four different whores and do sex invites. Don’t hold their hand after doing this. Once you’ve gathered up four to follow you, lead them to a bed and click on sleep and make sure to click down to select the protected or unprotected option, or else you’ll just rest for a set amount of time.
Alternatively, you could use a coop partner as one of them, with each of you having a flirty villager following you, that way you would only need one prostitute as the fourth.