Oxytocin makes the world go round. Well, it makes women fall in love, makes us pair bond. It's a hormone released when we have an orgasm. (I'm simplifying radically here.) Go read this nifty Nature article.
For men, apparently it's vasopressin that does the trick. Oxytocin and vasopressin are very similar molecules (nonapeptides with a sulphur bridge, if you're interested); they differ only in the position of two amino acids. So it might not be too far fetched to think of someone coming up with a synthetic hormone that could work on both women and men. Sounds simple, doesn't it? Take a pill, fall in love. But, like all those fairy tales about love potions, unexpected consequences would be inevitable. What if you pop the pill and then open the door to the UPS guy? Plus, I think oxytocin is destroyed in the GI tract, so would have to be injected. Or sprayed up the nose. Or put in an eye-dropper.
The spray thing is interesting. Imagine a plane at 40,000 feet, a love terrorist running down the aisle spraying... I don't think anyone's done any experiments on polyamory and oxytocin. I don't think they've experimented with cross-sexuality. Would a straight girl fall in love with her best friend? Would those married to other people not on the plane fall in love with the person they don't know sitting next to them? Would any of these instant lovers choose to take the antidote when they landed? (Could a pilot who has just fallen insanely in love land a plane safely?) Would Government Scientists, in their Race Against the Clock, come up with the antidote In Time?? (In time for what?) What if the plane was Air Force One?
You tell me.