She was hesitant to agree to his terms, but knew that she must. He shouldn't be the only person in that marriage revealing the ugliness of secrets they'd tried to hide. Both of them were guilty of being the worst sorts of spouses. If there was any hope of a better relationship for them in the future, which Hermione still wasn't entirely certain was possible, they had to get all of the ugliness out and on the metaphorical table. With a nod of her head, she accepted because she was tired of the secrets too.