Weiner is headed to joint today

ANTHONY Weiner’s 21 months of hard time starts Monday.

The disgraced former congressman is to begin serving his sentence for sexting with a 15-yearold girl. Weiner repeatedly encouraged the girl, who made plain she was underage, to get naked and fondle herself while he watched via Skype, court papers show.

He is expected to serve time at Federal Medical Center Devens, which is 40 miles west of Boston.

At his sentencing in September, Weiner (photo inset), 53, asked to be allowed to continue sex addiction treatment.

Devens is one of only nine federal prisons that offer the treatment and is the facility closest to New York.

Weiner’s wife, Huma Abedin, 41, has filed for divorce. The two have a 5-year-old son. In 2015, Weiner notoriously sexted a picture of his bulging underwear — while his son slept next to him.

Weiner, once a rising star in the Democratic Party and a City Hall hopeful, sobbed at his sentencing, telling Judge Denise Cote: “I was a very sick man for a very long time.”

He wore his wedding band at the proceeding, but it’s unclear whether he can take the ring with him to prison.

Devens’ policy says inmates can wear only plain wedding bands valued at less than $100.

Weiner’s sexting habit derailed his career as a congressman, as well as his bid to be mayor of New York — before it landed him in prison.

On Weiner’s final day of freedom, there were no signs of him at his apartment building near Union Square.

Abedin, who did not attend her estranged husband’s sentencing, did not appear to be at the apartment.