The really explicit phrase is doors of perception.

She co-wrote "Sister Morphine" which is featured on the Stones' Sticky Fingers album. The pair was flying to Italy on a leg of her world tour promoting Easy Come Easy Go. Her father Major Robert Glynn Faithfull was a British Army officer and professor of psychology.

Marianne Evelyn Faithfull (born 29 December 1946) is an English singer songwriter and actress whose career has spanned five decades. Faithfull's subsequent solo work often critically acclaimed has at times been overshadowed by her personal history. From 1966 to 1970 Marianne Faithfull had a highly publicised romantic relationship with Rolling Stones' lead singer Mick Jagger.