A former MTA coach cleaner was subjected to frightening homophobic bigotry by his co-workers in Grand Central Terminal — including some who’d sing a song about killing gays, an explosive discrimination lawsuit says.

“Kill them f–kers dead,” one of Reginal Jenkins’ cruel colleagues sang to him as others laughed, the suit says.

“It was crazy,” Jenkins, 40, told The Post. “I was scared.”

And after he complained, he found himself out of a job. Now he’s suing Metro-North and the MTA for discrimination and emotional distress.

“It’s outrageous,” said his lawyer, Vincent White. “He was singled out for making complaints about truly disturbing behavior.”

A rep for the MTA declined comment, citing the pending litigation.