"But-" Spock stopped himself, wanting very much to discuss the matter more completely. However she'd said she didn't want to dwell on it and he didn't want to risk upsetting her again. He couldn't really explain why - it had far more to do with merely being alone in this place - but he knew he didn't want to so he fell silent and instead nodded his compliance.
When she spoke again, he had to agree with her logic. "That would seem to be the wisest course of action," came his acquiesce. Briefly the thought flickered through his mind that he could easily out-run her and therefore it might be best if he were to go outside, but the thought was shot down almost instantly. Not only was it wholly illogical for them to split up, some part of Spock simply didn't want to leave her on her own either.
So instead, he simply pulled open the door and glanced at her with a slightly arched brow. "Would you care to go first?" he asked politely. He honestly couldn't say whether he hoped she'd say yes or no.