Father of the Bride Part II (1995)
Written and directed by husband-and-wife team Charles Shyer and Nancy Meyers, who brought you Baby Boom, this film also stars Diane Keaton in a maternal role as Nina Banks. Steve Martin is at the center of the story as her husband, George, a grandfather-to-be who learns he's also a father-to-be again. Martin Short plays a wacky interior designer, Frank, while Kimberly Williams is Keaton and Martin's pregnant daughter, Anne. And of course the dual-pregnancy storyline leads to mother and daughter giving birth at the same time. Everything turns out well, but not before Martin's character has a few hilarious freak-outs about becoming the parent of a newborn again so late in life.