Spike hopes that the Doctor isn't actually trying to watch his language towards an evil squid-thing. That thought would be more distracting if he didn't catch the movement jutting towards the door.

The hesitation he shows may have something to do with the tempting option of shutting the door and locking themselves inside -- but unfortunately, he remembers how well that's gone before. Without a purposely chosen curse muttered under his breath, he yanks the discarded blanket, and runs out the door.