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).
Marianne in fact had a great comeback and did her best work in the 80s and 90s. Recently her health has failed.
I saw her live in a nightclub in San Francisco in 93. She was no longer a sweet soprano; she sang in a whiskey/cigarette voice like Dietrich, and was awesome.