"Seventeen Come Sunday", also known as "As I Roved Out", is an English folk song (Roud 277, Laws O17) which was arranged by Percy Grainger for choir and brass accompaniment in 1912 and used in the first movement of Ralph Vaughan Williams' English Folk Song Suite in 1923.
It is one of those which earlier editors, such as Sabine Baring-Gould and Cecil Sharp, felt obliged to soften or rewrite for publication.
Early broadside versions were sad songs focused on the abandonment of the girl by the young man.
A censored version published by Baring-Gould and Sharp substitutes a proposal of marriage for the encounter.
So I went down to her mummy's house, when the moon shone bright and clearly, She did come down and let me in, and I lay in her arms till morning.
She took her by the hair of her head, And down to the room she brought her, And with the butt of a hazel twig She was the well beat daughter.
However the details of the texts are so different that the Roud Folk Song Index classifies them separately.