If I'd actually had a baby die (as friends of mine have), how brutal it would be, at a dinner party perhaps, if someone who didn't know their history casually made a dead baby joke. Worse, if that set off a round of dead baby jokes (as that is often how such conversations go). And they would sit there, their hearts breaking, while their friends laughed and laughed. Hilarious.
I understand the use of black humor. Humor is almost always founded on pain, even with something as simple and iconic as slipping on a banana. But it seems to me that the purpose of black humor is often to transform that pain, to offer up, in fact, your own pain, in order to help others move through theirs. Humor can be transformative, and it can help us survive -- that's what redeems what would otherwise be cruel.
A casual, aggressive gang rape joke, made by a man and directed to a woman, fails utterly at anything transformative or redemptive. It's just petty, and mean, and heartless. And no, it's not funny.