When a man gets too excited by his activities and creams his pants, casting babybatter all over the zipper region.
(v. tr.) zipperbabied, zipperbabying, zipperbaby: The act of creating a zipperbaby.
"My friend made a zipper baby during an 8th grade dance. He blamed it on the combination of pelvic movement and her perfume."
"Andy Samberg wrote an awesome song about making zipperbabies, it's called 'Jizz In My Pants'."