Sulu was noticing the fact that Ianto was not really feeling the mention of moving walkways, and so he winced, going quiet except for a murmured, "yeah," and a glance at Ianto's face in between steps. He slid his hand up a bit, keeping it well away from Ianto's stomach - after all, pressure there would be incredibly disastrous for the both of them. "When we get to the bottom of the stairs, we'll sit down." His tone clearly indicated that he knew what Ianto was going to need to do. For a moment, he wished that Jack hadn't left them, but then he realized that he and Ianto wouldn't be set for a date if he hadn't. Hopefully, throwing up wasn't going to make Ianto regret that whole conversation.