When you're having sex, making out, or just cuddling and your arm gets trapped in an awkward spot ( Straight up, or bent at chest leaving hand by your face) that renders your hand useless.
Think Ricky Bobby interview "I'm not sure what to do with my hands..."
I was in bed cuddling with my sweetie and somehow my arm got trapped between us, bent at the elbow, with my hand just sitting between our faces.
I declared "Awkward Hand Syndrome" and proceeded to "Vogue" various hand gestures including "thumbs up, thinking man,nose picking, and surprised guy"