G-FORCE ONE COMPLETES 18 parabolas during our two-hour flight, which traces a 100-mile-long rectangle within a designated FAA-controlled airspace over the Atlantic Ocean. It takes four parabolas before I determine that the only way to get close to Ashley is to seize her hand during the ascent, then yank her toward me the moment we start to levitate.

By our 15th parabola, we're feeling increasingly queasy. Weightlessness induces a kind of seasickness. To shake off the nausea, I shut my eyes as the plane slides into another parabola, but with my eyes closed I can't tell which way is up. I might be pitching and rolling, or hovering motionless a few feet above the deck. My senses, on the other hand, are on overload. I'm hyperaware—touch, taste, sound, and smell are remarkably crisp and strangely amplified. My skin feels loose and relaxed. I hear the dull thuds of bodies flinging into walls and the whine of the engines tearing through rarefied air.

In this condition, sex would probably be mind-blowing—that is, if I could get within groping distance of my wife. G-Force One rises into another parabola, but before I can get to Ashley, a chubby Mensa dude with a knotty beard rams into my knees and sends me barreling like a bowling ball into a cluster of other passengers. I score a strike. Globs of water and M&Ms are dancing through the cabin. G-Force One climbs again, and this time Ashley throws her legs around my waist, clasping them tightly behind my back. Firmly entwined, I pull her head toward me, ramming my lips into hers like an overeager teenager. Technically, we kiss. But it's not pretty.

Thirty seconds isn't enough to do much else, obviously, especially with a planeload of gawking onlookers. But our quest is not in vain. On the next parabola, we manage to hang on a bit longer, embracing face to face in an askew missionary position before spinning vertically and crashing feetfirst into the ceiling. We persist, lurching and slinging ourselves into various positions that fall somewhere between "clumsy tantric" and "drunken Twister." Sex in space, where a gentle hip thrust could launch Ashley into an uncontrolled death spiral, is going to require the aerial agility of a dragonfly.

That's OK. I'm willing to practice.