Ex-Rep.-turned-teen-sexter Anthony Weiner showed up in Manhattan Supreme Court on Tuesday to register as a sex offender.

Weiner, 54, strolled into 100 Centre St. in the early afternoon and headed to the NYPD’s Sex Offender Monitoring Unit.

The estranged husband of longtime Hillary Clinton aide Huma Abedin was inside the 14th-floor office for about 20 minutes. Officials took his picture, fingerprints and a DNA sample, and he was registered as Level 1 sex offender.

Later, as he strolled on Worth Street, Weiner mocked a photographer and a reporter who pursued him for struggling to keep up with his long strides.

“Come on, catch your breath,” he quipped.

Weiner — who last week didn’t show up for his first appointment to register — was released from a Bronx halfway house on May 14.

He pleaded guilty to sexting rape fantasies to a 15-year-old girl in 2017 and was sentenced to 21 months in prison. The once-promising politician by then had already torpedoed his career with a series of sexting scandals with women.