and the answer is?
Mick Jagger!
Lennon and Jagger had a well known rivalry.Jagger often boasted about his "bird",Marianne Faithful.Marianne was "green" (young),she could sing (several huge hits in Britain,at least one in the US),and she could "swing" (she was the woman found wrapped only in a carpet during that infamous drug bust of the Stones early in their fame).