Ernie kept his arms around Hazel, in part because he was afraid to move and part because it was nice, and he didn't mind the excuse.
It would have been nicer, of course, if there weren't members of the IS (and he could tell now, that that was definitely who they were) on the other side of the door looking for them.
Ernie bit his lip, just staying still and silent and hoping very much that Hazel didn't mind the fact that they were very close together in a very tiny room. He didn't mind. And wouldn't, perhaps, mind taking advantage of the situation (for he was seventeen, male, and in a small dark room with a pretty girl, after all), if he wasn't so damn polite.
And hiding from the IS. That tended to put a damper on the romance.