"Sweet Pea" is cute nickmane for a loved one, usually a child (Swee'Pea is the name of a baby in the Popeye
universe). Like their song "Sugar," it's a sweet title for a salty song, but in this case with an alternate spelling. Crosby, Stills & Nash used the "sweet/suite" homophone on a very different song: "Suite: Judy Blue Eyes
"Suite-Pee" never shows up in the lyric.