A 34-year-old man has pleaded guilty to two charges of sexual activity with a child.
Christopher Clark, formerly of Leaze Road, Melksham, carried out the offences on the girls, aged 13 and 14 years old, between the end of May and mid August last year.
And he also admitted a charge of attempting to have sexual activity with the younger girl between during a similar period of time.
At Swindon Crown Court, Clark denied two counts of causing a child to watch sexual activity and also pleaded not guilty to another count of sexual activity with the 13-year-old and prosecutors said they will not be seeking a trial on those matters.
The case was adjourned to Friday, April 5 for a pre-sentence report and Clark was released on bail on condition he does not go to Dilton Marsh or contact witnesses.
He must also register as a sex offender, and the period he will have to keep registering will be determined by the final sentence.