An indecent act by Jayden Takarangi was labelled "stupidity" when he appeared in court this week.
Takarangi pleaded guilty to two driving while disqualified charges as well as an indecent act charge when he appeared in the Whanganui District Court on Wednesday.
His lawyer, Stephanie Burlace, said it was an act of stupidity and was a situation where a couple of guys were egging each other on.
Since the incident, Takarangi had shown remorse by making a $200 donation to Women's Refuge and writing a letter of apology to the victim of the indecent act.
"It's really been a big shake-up, and he's turned it around and is really been making changes," Ms Burlace said.
"He has attempted to put right as much as he can. He was 19 at the time with no history apart from the driving offences."
Judge Philip Crayton said in a short space of time Takarangi had shown poor decision-making skills on four occasions.
While the indecent act was no doubt stirred up by others, "it doesn't address how it must have been for your victim".
"She had the right to be going about her business without yobbish acts directed at her."
Mr Crayton said when Takarangi took the time to reflect on his actions he could see the wrong.
"You know you are making poor decisions."
Takarangi was sentenced to 12 months supervision and was disqualified from having a driver's licence for six months.
Judge Crayton said if Takarangi drove again in that period he could guarantee he would be "booking himself a bed in the cells".