Arm, Wherefore Art Thou Sticky

For a while now, I've been noticing that, when I get off the plane, my forearms and only my forearms are inexplicably sticky. I never gave it much thought, because airplane cabins are seething cesspools of germs and virii, and so I just take a shower instead of trying to itemize the source of every ick. But today as I was handing a passenger a carbonated drink, the sun filtered through the window and lit up the eight-inch fountain of spray that the bubbles spritz up over the drink and onto my arm.
Another mystery solved.