(n.) The orgasm of a man achieved while he's still wearing his pants.
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.
"That stripper made me buy her a new outfit because she saw my zipperbaby and got pissed."
"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'."