A FATHER-OF-FIVE who molested a 16-year-old babysitter was snared by his grown-up son who lay in wait and caught him in the act.

Andrew Baker, 55, had been boozing at a Christmas party when he heard his daughter had got a young girl to look after her kids in a flat lower down in the Park North block.

His grown-up son went down to check everything was all right in his sister's flat when realised his dad was missing from the do in the early hours.

Realising the babysitter was uncomfortable with Baker, who did not know he had been followed, the son hid in the room when the teenager tended to a crying child.

And moments later his father, who had earlier been at the party with his wife, sneaked in and started to paw at the girl as she tried to get the little one back to sleep.

Philip Warren, prosecuting, told Swindon Crown Court the teenager was looking after Baker's grandchildren at a flat on Friday, December 18, 2015.

He said the defendant was at his son's apartment a few floors up in the block and, hearing she was babysitting, he disappeared.

After appearing at the door Mr Warren said the girl felt compelled to let him in and was uncomfortable with his drunken behaviour, asking her to join him on the sofa.

Realising his dad had disappeared his son went down to the flat and saw the babysitter, who he was friends with, was unhappy about Baker being there.

When the baby started to cry she went through and gave her some milk and lay down on the bed next to her with the lights off trying to get her back to sleep.

Baker then went in to the room and got into the bed and put his hand on the girl's groin, and she screamed in terror.

Mr Warren said as she fled the room his son leapt out, turned the light on and confronted his dad.

Baker, of Whitbourne Avenue, initially pleaded not guilty saying his son and the girl were both lying but before a jury could be sworn in he admitted sexual assault.

Claire Fear, defending, said that her client could recall nothing of the incident but accepted if they said he did it, he must be guilty.

She said his wife was standing by him, he had a good work record and he had no similar previous convictions have been out of trouble for 20 years.

Talking of his drinking she said: "He has reduced his intake considerably, he only drinks at home with his wife and his daughter."

Jailing him Judge Tim Mousley QC said: "I am quite satisfied that you went down to the flat with the intention of sexual assaulting her and it was not something that happened on impulse.

"Custody is inevitable: that night you had decided that you were going to assault her.

"The assault took place in a location where she ought to have been able to feel safe and her fear of what she though you might do to her must have been obvious to you but you persisted, and you were drunk."

He jailed him for 17-and-a-half months and imposed a 10 year restraining order; the same period he must register as a sex offender for.