i would love to see threesomes at some point in time; would also love to see those flag pattern they Shey suggested, the ability to "peek" at others having sex and watch them, would love to have couch sex (this i imagine would just be a background change and adding a interaction area for the couch), the ability to give a key to spare room keys to others so they have free use of the room, some sort of mini-game like darts in the hotel rooms would be a nice addition, gives something else to do during party's 
but most importantly a different payment system.
edit, stick the tail on the girl would be a fun party game i think.
but most importantly a different payment system.edit, stick the tail on the girl would be a fun party game i think.