Spike's eyes grew bigger the further she went into her story and he just wanted to hug her tight. It seemed that he had almost lost the love of his life but needed to be patient near her. Rarity found it rather cute that he was in love with her. Though the signs were sometimes too obvious to miss but she never appreciated anypony to just hug her just out of the blue. Especially with her changed state and colder body temperature it would only raise suspicion around her. Foreshadowing, one could have called it.