He said the earliest point he could remember engaging in sexual intercourse was the day after her 16th birthday.
Asked if the relationship was sexual when she was 15, he replied: “That’s not true.”
He said he had no recollection of ever recording any of their sexual encounters.
Under cross examination by the Crown, he disputed that the women were telling the truth.
He told the court he has been a police constable for more than 10 years and was previously a special constable, but was currently suspended.
Williamson, of Burra, denies the series of charges alleged to have been committed at locations in Shetland between 2014 and 2022.
The trial, before judge John Morris KC, continues.
