A thief used his teeth to bite through a lock and steal a bike on Sept. 16 in Kips Bay, police said. View Full Caption Flickr/Zach George

KIPS BAY — A thief used his pearly whites to chomp down on a lock and free a bike from its restraints, authorities said.

A police officer spotted Nathaniel Gaines, 53, casing bikes along East 25th Street between Lexington and Park avenues on Sept. 16 at 11:08 a.m. and watched as the alleged thief chose his mark, according to a criminal complaint from the Manhattan District Attorney's office.

When Gaines found a bike to his liking, he began to twist the lock with his hands, but when it failed to open, he sunk his teeth into the lock, according to the report.

Eventually his gnawing caused the lock to break, police said. Gaines then snatched the bike and began to walk away, the report said.

Despite his noshing skills, the alleged thief did not make it far, and officers rushed to arrest him for possession of stolen property, criminal mischief and petit larceny, according to the criminal complaint.

The man was also charged with possession of burglary tools after police found a pair of bolt cutters in his backpack, according to a report.

A judge sentenced Gaines to seven days in jail after he pleaded guilty to the burglary tool charge, according to court records.

Other notable crimes in the 13th Precinct include:

►Officers arrested a man after he exposed himself on a Midtown sidewalk on Sept. 16, according to a police report.

John Pfeiffer, 69, pulled his pants down on E. 27th Street at 2:49 p.m. between Fifth and Madison avenues, exposing his genitals and also waving around a colored dildo, police said.

Officers hauled him in and charged him with public lewdness, according to a police report.

It was not immediately clear if Pfeiffer had secured an attorney.

► Police arrested a man in Union Square on Sept. 15 after he picked a fight with another man in Barnes & Noble, according to a police report.

The argument began after Thomas Fonseca, 60, was walking about of the bathroom of the book store at 3:58 p.m. and began harassing the other man, police said. Fonseca allegedly spat in the man’s face and harried him until the man had "no choice to defend himself," according to a police report.

When the pair started brawling, Fonseca allegedly tried to toss the other man down an escalator, police said.

Officers arrested Fonseca for assault.

It was not immediately clear if Fonseca had an attorney.

