The man who allegedly

killed his girlfriend’s 3-year-old son

wept in court Friday as the boy’s sincerely heartbroken dad scoffed at the display of “crocodile tears.’’

Salvatore Lucchesse, who is accused of savagely beating Jaden Jordan last month, was arraigned Friday in Brooklyn Supreme Court on an ­indictment charging him only with assault and endangering the welfare of a minor.

But Acting DA Eric Gonzalez said the charges “are expected to be upgraded’’ because the child eventually died of his injuries.

Guseyn Aliyev, Jaden’s father, derided the defendant as a ­“scumbag.’’

“Crocodile tears. Where is this tough guy who beat an innocent 3- year-old child to death?” Aliyev said. “He has the nerve to say he’s not guilty. So who did it? Jaden didn’t fall from a third-floor window.”