“Oh, my God — I can’t even believe I’m hearing this.”

That’s what commentator Lauren Ashburn blurted out on the set of Howard Kurtz’s CNN show “Reliable Sources” on Sunday. Under discussion? Herman Cain, the media and sexual harassment.

Ashburn, as it turns out, had strong reason to gasp. She was responding to one of the great refrains of the Herman Cain sexual-harassment story — that there’s not enough detail, not enough proof, not enough solidity to the story.

Matt Lewis of the Daily Caller, when asked about the story, said, “The problem for the media is there’s no stained blue dress.”

And: “We don’t have any proof or evidence” to back up the allegations.

Then Lewis essentially dismissed the accusations against Cain: “Herman Cain was definitely damaged by these accusations, but I don’t know that they’re deadly to his political future unless there is some proof, because anybody could be accused. You could be accused; I could be accused.”

That’s what prompted Ashburn’s “OMG” — as it should have.