The legendary Hollywood heartthrob is famous for dating a string of beautiful women including Lara Flynn Boyle and Anjelica Huston but he admitted that at the age of 73 he now doubts his power over the opposite sex.
He said: "I`m definitely still wild at heart. But I`ve struck bio-gravity. I can`t hit on women in public any more. I didn`t just decide this, it just doesn`t feel right at my age.
"If men are honest, everything they do and everywhere they go is for a chance to see women. There were points in my life where I felt oddly irresistible to women. I`m not in that state now and that makes me sad."
Jack famously cheated on Anjelica Huston with Rebecca Broussard, ending their 16-year-romace but the `How Do You Know` actor claims the split broke his heart and he has never recovered.
He told Live magazine: "The reality was that I was annihilated emotionally by the separation from Anjelica. That was probably the toughest period of my life.
"I may have made a mistake but I don`t want to go back and correct it. I would rather deal with it."
Jack has five children from different relationships, Jennifer 47 with former wife Sandra Knight, Caleb, 40 with Susan Anspach, Honey, 29 from a relationship with Winnie Hollman and Lorraine, 20 and 18-year-old Ray from his romance with Rebecca Broussard.