Fantasies are a form of release. They are all quite acceptable....as long as they are legal and between consensual adults and nobody gets hurt. Of course in the privacy of your home and your head you can do whatever you want. Well, not quite: the internet comes into play and we all know of pedohile rings etc. But then say, you are single and you fantasize about having a 3some. Nothing wrong with that...and also possibly very nice to do for real, so why not. It may even involve some sort of play like domination or submission or bondage...whatever. You may find the experience pleasant.......or maybe once will be enough and you'll prefer to go with the fantasies in you mind. The key is always to keep things Under control and pleasant for all. We all know of circumstances (read in the papers etc) where things went tooooooo far and a person got hurt, indeed died and the other(s) ended up in jail like forever. Control is the key word. Enjoy.