David Blair, 51, admitted indecently assaulting a woman, aged 24 at the time, while she was staying over at his then home in Newtown after a night out with his wife in 1998.
She recalled waking up to find Blair standing over her naked and touching her breasts and body under her clothing.
He also pleaded guilty to a similar offence involving an 11-year-old girl three years later.
Blair, now living in Jedburgh, admitted a charge of lewd and libidinous practices towards the girl by touching her breasts while she was sleeping in January 2001.
He originally denied both offences but later owned up.
Jedburgh Sheriff Court heard the girl had “gone off the rails” after the incident but it was only last year that she felt strong enough to report it to police.
Defence lawyer Mat Patrick asked that a psychiatric assessment be carried out on his client, already on the sex offenders’ register.
That request was accepted, and sentencing was deferred until Tuesday, April 17.
However, sheriff Derrick McIntyre warned Blair he faces being put behind bars, saying: “You should be under no illusions – you are probably facing a prison sentence.”