Just the idea of zero-g sex makes me laugh. Just the thought of certain..."Fluids" floating back up into ones face makes me both laugh and gag at the same time.
People are really unattractive in zero-G because fluids don't drain properly in the body so everyone gets puffy and smelly.
Way to kill my fantasies, bro. 
Don't worry, there's still SpaceShipTwo. You'll be able to get four minutes' worth of weightlessness for a minimum of expense.
Anyway, this thread has motivated me to do some reading on this, but I do agree with Mongoose to some extent. This is an awfully expensive and nasty (for the couple involved) proof of concept that we can send someone around Mars, isn't it? Especially with not as much of a research bent as there could be.
You're forgetting that plenty of research will be involved in putting together the life support systems, radiation shields, etc., as well as psychological and physiological accommodation.
Incidentally, I've been keeping my eye out for any attempts to fly this in Orbiter Spaceflight Simulator, and sure enough, one of the intrepid modders at the
Orbiter forum is on the case. He's already done it with the Delta Glider, and he's going to make an attempt with the Dragon and Falcon Heavy this weekend.
