Here's everyone's worst nightmare with crowded trains: Those perverts who rub themselves on you. The police have a photograph of one grinding suspect who preyed on a person on an F train.

According to police, on Friday, November 12, at 8:35 a.m., a man rubbed himself against a victim on a northbound F train at DeKalb Avenue.

Police say the suspect is a black male who was seen wearing a tan skull cap and dark colored pants. Anyone with information in regards to the sex abuse is asked to call Crime stoppers at 1-800-577-TIPS (8477). The public can also submit their tips by logging onto the Crime stoppers website at WWW.NYPDCRIMESTOPPERS.COM or by texting their tips to 274637 (CRIMES) then enter TIP577.

Keep in mind that if convicted, it might only be a misdemeanor offense because NY State's highest court doesn't think perverts rubbing up against people (and ejaculating on the) isn't a felony,