The Player augment is not that hard to get if you know where to look for the four regular Prostitutes. These areas include the Mercenary Camp and Bowerstone Old Quarter. You can also sleep with any NPC of the correct sexual orientation who loves you with 'flirty' under their trait description by holding their hand when you go to sleep. Theoretically then you could have 5 people in any orgy fairly easily. Also you don't have to hold hands with the prostitutes. Once you've done the 'sex invite' they will follow you anywhere, including fast travelling, until you've slept.