There's a humorous song by The Kerries on a Major Minor LP 1967 called McTaggart. I can transcrbe the song if you want when I get a minute, but the gist of it is that McTaggart falls in love with various girls only to be told by his father that '....Blood is thicker than water, I've sown wild oat from John O' Groats and Jeanie/Rosie etc is my daughter' The last verse concerns McTaggart telling his mother who informs him that ' ..you can mary Jeannie/Rose etc because your father's not your father' Cheers, Jim Mclean