Perhaps it is time for the truth...
Oh Kenneth, my darling,
Please get up off your knees, it is no position for a prince.
Oh Kenneth, I have had bad days before but none so wretched as today. After I received your email I went to the beach and walked and walked for miles and miles. What to do? What to do? I wish I knew.
What was a pleasant correspondence has grown into a multi-headed demon with the news of the forthcoming ring! All of a sudden it has become really serious and I am scared, Kenneth, I am very afraid.
I cannot have children, Kenneth. I am sorry. I am very sorry. Perhaps I should have told you earlier but I never thought that it would get this serious. I have consulted all manner of doctors and always it is the same message: I am just not able to have children. Maybe it is due to syphilis, maybe it is just genetic, I don't know. (I'd put my money on genetic.)
And I do not want to break your heart, my darling. I have tried all sorts of ways of taking myself out of your life, to leave you free to find someone else and raise a thriving little clan of princes and princesses and live happily ever after. Each time I failed miserably.
I want you to be happy, Kenneth, truly I do. But I cannot make you happy. Certainly not long term. (That's true enough)
Oh Kenneth, what am I to do?