The four complainants, two of whom were to give evidence at the trial, had each stayed at the defendant's home for varied periods of time.
One complainant with a significant intellectual impairment had lived with the man for years and said in court that she remembered first being touched by him when she was 13-years-old.
She told the court she would feel scared when he was "getting all crazy" and hadn't told anyone about what was happening as she feared she would get into trouble.
This touching eventually progressed to full intercourse and there were also occasions when he made her watch pornography, she said.
While most of the offending occurred in a household setting, the court heard she had once been in a car with the defendant who was driving when he parked in a secluded public place and forced her into a sex act.
"It was disgusting. It was yucky," she told the court.
In addition to the testimony of two complainants, the jury of eight men and four woman will hear from a psychologist and a detective as well as a number of recorded interviews.
The trial before Judge Bridget Mackintosh is continuing and is expected to last the week.