and it 's ... ... the chorus , with great laughter at mairead 's wide-eyed poor-maiden-finding-herself-suddenly-with-child pantomime , and then she sings the last verse ... now come all of you fair maidens , a warning take by me , and never let a sailor lad an inch above your knee , for i trusted one and he beguil-ed me , he left me with a pair of twins to dangle on me knee .