An Amesbury man was arrested this week after he allegedly showed his girlfriend's family his genitals, according to Waltham Police.

Kevin Donaldson, 47, of Amesbury, is facing charges for indecent exposure, assault and battery on a police officer and threatening to commit a crime, according to Waltham Police Sgt. Tim King.

Donaldson, was arrested on Dec. 31, 2012 at 5:20 p.m. after police responded to a report of an unwanted person at 9 Waltham St., the home of Donaldson's girlfriend, King said. Police arrived and learned that Donaldson had been coming down the stairs of the home, where his girlfriend's family was gathered, and displaying his genitals, King said. The family asked Donaldson to stop, but Donaldson repeated the behavior, King said.