Elevator-stab fams agonize at B’klyn trial

A PERVY straphanger pleasured himself in front of a fellow commuter in Brooklyn, police said Wednesday.

The 29-year-old woman subjected to the sicko’s self-love on a northbound Q train Tuesday morning snapped a picture of him before she hopped off at the Sheepshead Bay station, cops said.

In the photo (inset), released by police Wednesday, the suspect is seated, lips pursed, in front of a poster for the Broadway hit “Kinky Boots.”

He is a black man in his 20s, with hair in short braids, and wearing a red jacket and blue jeans.

Cops are asking anyone with information to call Crime Stoppers at (800) 577-TIPS. THE FAMILIES of a boy and girl slashed in a Brooklyn elevator four years ago squirmed and cried Wednesday as a prosecutor told jurors about the brutal attack that left one of the children dead.

Relatives filled a Brooklyn courtroom where Assistant DA Patrick O’Connor described a “frenzy of stabbing and slashing” that killed 6-year-old Prince Joshua Avitto and left his 6-year-old best friend Mikayla Capers near death. Across the room sat Daniel St. Hubert, 30, who is charged with murder and attempted murder after cops linked his DNA to the grisly scene.

“Every day I think about what he would be like at 10,” said P.J.’s mom, Aricka McClinton.

McClinton and other loved ones wore charms around their necks that held a pinch of P.J.’s ashes. The children were attacked June 1, 2014, in an elevator at the Boulevard Houses in East New York.

O’Connor said Mikayla and P.J. were laughing and playing when St. Hubert pulled out a 9-inch steak knife and stabbed Mikayla 16 times, and P.J. 11 times.

St. Hubert’s lawyer, Howard Greenberg, said there was no blood on the clothes his client wore that day. He described the DNA match as “junk science.”