white Rubicon

The point during masturbation when you know you're going to cum, and there's nothing you can do to stop it.

"I can't pull out now, I just passed the white Rubicon."

irony rubicon

The point when someone who engages in an activity ironically becomes sincere in their engagement in said activity.

"What's up with Bronies?"

"Oh, they've crossed the irony rubicon."