"Eighteen Or Over" Lolly Rogers, a wedding dress designer, never married Nels, the father of their three children. Scarred by her serial-marrying mother, Lolly believes there are no guarantees in love or marriage. Because of this, Lolly made Nels sign an ironclad agreement, committing them to being a two parent household until all their kids were 18 or over. A month before their youngest daughter's 18th birthday, panic sets in as Nels and Lolly's relationship is about to expire. When the secret is revealed that they've never married, their oldest son announces his plans for a plural marriage to two women. As Lolly searches for a way to keep one man committed without marriage, her son struggles to keep two women committed by finding a way to tie the knot.