When police threatened to break a glass door to arrest Kurt James Clement, he placed his 2-year-old son against the glass.
Before Judge Tony Walsh in Masterton District Court on Thursday, the 25-year-old truck driver of Carterton pleaded guilty to male assaults female, wilful damage, resisting arrest and obstructing police.
Police then withdrew a charge of assault with intent to injure.
Prosecutor Sergeant Garry Wilson said that on June 19 Clement, his partner and two children were at a party at a friend's house where Clement became "agitated" and an argument developed between them.
The argument continued at home and his partner tried to call police.