https://vm.tiktok.com/ZNeK5vKMw/
This is literally Bill's mentality in BiS once he stops viewing her as just prey.
To explain a bit, I've mentioned in one of the chapters that Bill kept portraits of all the lovers he'd had as a vampire, with representative flowers for each one of them. In Bill's view, he values and respects women immensely, and treats them highly and reverently, almost in a worshipping manner.
To him, adoring a woman is the equivalent of being human again, it awakens a sense of humanity in him, the inner need to cherish and protect, and that's why he barely ever touched Rachel, barely kissed her, or almost never bit her, because he was trying to maintain her chastity, her light, her purity, not wanting to completely taint something that was meant to be kept intact.
His level of respect for her is just THAT high. But at the same time, it was never about Rachel herself. She was a mere vessel, an idealization of what a woman should be or what he searched for in one; he associates women with light and purity. But what he TRULY seeks for is still God. When he's searching for the light in those women, he's actually looking for God, something of semblance that would momentarily fill the void of what he'd lost along with his soul.
The thing is, he never had any intention of committing to a lover ever in his life before, because he only wanted to observe and admire the lover, then let her leave in peace (painless death, maybe). But now, because of Tom's absolutely twisted mind, he's basically stuck with Rachel, which is mortifying to him.