A subway perv was caught apparently masturbating Wednesday on a Bronx-bound D train during rush hour.

Surrounded by bags of his belongings, the man was spotted putting his hands in his pants and making a back-and-forth movement with them.

“His head sank down and he was still. He seemed to be dozing off. Then he started again a few minutes later,” said a passenger who witnessed the scene after boarding the train at West 4th Street.

The quick-thinking straphanger recorded the seemingly lewd act.