Ian Cowan (65) pleaded guilty at the High Court in Livingston to three serious sexual offences.
The widower admitted raping the babysitter in the bathroom of his then home in Linlithgow on October 2, 1992.
He also admitted two charges of indecently assaulting the older woman by repeatedly forcing her to have various forms of sex with him against her wishes over a six-year period nearly 25 years ago.
He had previously served nine years in prison for attempting to rape two young girls in his care.
Judge Lord Burns sentenced him to six years and three months in prison for the latest crimes.
The judge discounted the sentence from seven years because the father-of-two’s guilty pleas – offered on the morning he was due to stand trial – had avoided his victims having to give evidence against him.
The Crown accepted not guilty pleas to a further seven historic charges, alleging rape, child sexual abuse, assaults and threatening behaviour with a shotgun.
Passing sentence, Lord Burns told Cowan: “You have pleaded guilty to the indecent assault of (the woman) over a six year period during which you subjected her to a course of degrading sexual abuse which not only caused her physical pain and harm but also distress. She continues to suffer from the effects of that to this day.
“You also pleaded guilty to the rape of a young girl who was babysitting in your house and who you proceeded to abuse callously in your house. You have an analogous conviction for the attempted rape of two girls.
“I have full regard to the age that you now are and, importantly, to the fact that the most recent offences here occurred some 24 years ago, and you have not offended since. I also have regard to the health issues from which you suffer.
“You don’t appear to pose a risk to the public but this sort of sexual offending must be dealt with by significant sentences of imprisonment. The sentence I impose is a cumulo sentence of six years and three months.
“You will remain on the sexual offences register indefinitely. That sentence will start today.”
John Keenan, defending, said Cowan had lived on his own in Dunfermline, Fife since the death of his third wife in 2015.
Cowan showed no emotion as he was led away to the cells but one of his victims, who was in court to see him being sentenced, quietly wept and was comforted by her family.
Following Cowan’s fresh admissions yesterday, Advocate depute Margaret Barrow revealed that he had been convicted in January 1998 of the attempted rape of two young girls and sentenced to nine years in prison.
One of the girls was aged between 6 and 10 and the other between 9 and 14 at the time Cowan abused them more than 30 years ago.
Outside court, the woman who was the victim of Cowan’s sordid behaviour for more than five years, spoke of her relief that he had been taken off the streets.
Surrounded by her family, she said: “We’re happy with the outcome. It’s a brilliant result and it couldn’t have gone any better.
“We’ve been in suspense for so long waiting for this day. Now we’re off to start trying to piece our life back together and start living again without this hanging over us.”