Derek Munro admitted to a jury that he was in love with one of the young women but said that the sexual contact that took place between them was consensual and took place after she was 16.
The court heard Munro lived with her at one stage. When interviewed about the allegation he told police he had left his then wife and children to be with her.
Munro, of Wigton Avenue, Alwoodley, pleads not guilty to six offences of indecent assault and eight offences of sexual assault.
The offences are alleged to have taken place between 1990 and 2013.
The prosecution claims six indecent assaults were specimen counts which related to offences said to have been committed against one girl during the 1990s when she was aged 14 and 15 and while he was in a relationship with her.
Seven sexual assault offences are alleged to have been committed against another pupil over a nine year period from when she was aged 14.
A third complainant is alleged to have been sexually assaulted on one occasion during a tennis lesson when she was 16.
Munro gave evidence yesterday in which he denied all allegations made against him.
His barrister Simon Myerson, QC, asked Munro: “Have you sexually assaulted (the second complainant)?”
Munro replied: “No. Never.”
Mr Myerson then asked if he had sexually assaulted the third complainant. Munro replied: “Never.”
The barrister then asked: “Did you have a sexual relationship with (the first complainant)?” He replied: “I did.”
Mr Myerson continued: “Did it begin before she was 16 years old.” Munro replied: “No.”
The jury has been shown a recording of the second complainant describing to police how Munro would rub up against her from behind during tennis lessons.
She also described how on one occasion Munro sexually assaulted her as he put a snowball down her top.
The jury has also been told Munro invited her to visit his villa in Marbella when his wife was not there so they could “have fun”.
She said Munro would often send her messages on MSN Messenger describing her as “sexy”.
On another occasion she said he appeared on a webcam and told her he was “excited.”
Munro denied that he had ever made any sexually inappropriate remarks towards the woman.
The trial continues.