Sen. Marco Rubio (R-Fla.) isn't budging from his refusal to say whether he has ever smoked marijuana.

In an interview with ABC News and Yahoo News published Monday, Rubio reiterated his darned-if-you-do-darned-if-you-don't reason for not addressing the question and cited a conversation he had with a concerned parent as justification for his posture.

"Someone came up to me and said, ‘You know, I enjoyed your book, but I want you to know, my son came up to me and said he doesn't have to get good grades in high school because look at Marco Rubio, he didn't do well in high school and look how successful he's been.' And that impacted me," Rubio said.

That's the downside of saying you have smoked marijuana, he argued — that people will think it's no big deal. He made the same argument at a February National Journal event.

On the other hand, if you tell people you didn't some pot, Rubio said, "they won't believe you."

The "bottom line," the Florida Republican said, "I don't think people should smoke marijuana."