I agree Caz. I do think the partner needs to be warned and deserves the truth but I do think something is wrong with her too. To be that desperate just seems sad. There was a man on Dr Phil years ago who was making love to his wife in the middle of the night and also pulling condoms off without her knowledge/consent. He seemed so scared of her leaving, and scared of not having more children on the way... it was like an anxiety thing.
I do think the fact that she's going to these lengths, when there is the ease of donors, means something has gone wrong.