She’d had one week with Giles before he fell ill, just enough to whet her appetite for the pleasures of the flesh. Before she’d learned of Jack’s adultery, she’d begun to imagine what it would feel like to lie with him, but she hadn’t allowed herself such a fantasy in three years. Instead, night after night she’d raged against fate for being so cruel, so unfair, as to give her only one week of bliss when other women had years and years of happiness. And now already some traitorous part of her called out, See how handsome Jack is! And he wants you.
He wants an heir, her wiser self told her foolish body.
*Yes, Elizabeth and I both know that according to the legalities of the day, her husband has rights to her body. However, she judges, correctly, that he'd be unwilling to force himself upon a woman who was actively resisting him even if didn't legally count as rape.