beyond the point of no return

Having passed the last opportunity to reverse one's actions or return to one's starting position. Once we sign this agreement, we'll be beyond the point of no return. We're committed for the long haul after that. Our only option is to keep climbing the mountain, because it's far too dangerous to turn back. We've gone beyond the point of no return, now. A: "If you're having second thoughts, you better speak up now. Once you marry him, you'll be beyond the point of no return." B: "That's not true—there's always divorce."