is speaking out about the incestuous affair between her half-sister Mackenzie phillips
, and their father, John Phillips
, of The Mamas and the Papas
Chynna, 41, says she received a call from Mackenzie in 1997.
"She said, 'I don't know why, but I just really felt the need to call you and tell you something that I think you need to know,'" Chynna recalls. "And she went on to tell me