I'm not sure if this happens at all stages of upgrading your villa, but it does at least when it's finished. There's an interactable, but non-voiced female Assassin who starts running away the moment you get close and press B. Following her, the screen suddenly jumps to a bedroom... Where she lies, seemingly exhausted, on bed. Can't interact with her. However, there are 2 other women in this room, who both seem drunk (and in my case there was a social chest too). The one closest to the bed can be interacted with, resulting in her lying next to the female Assassin in the same state. There doesn't seem to be anything else I can do. Is the game trying to imply Edward just had sex with the both of them? Perhaps something Ubi forgot to clean up?
Note: Just found this earlier post here too, but it had no replies and wouldn't allow any new ones either: http://www.gamefaqs.com/boards/705970-assassins-creed-iv-black-flag/67650252