'It's Sunday.'

This is said very much in the manner of a question rather than a statement, as he tries to ease the crick in his neck that always comes from sleeping in his office.

'Yeah, put the kettle on. I'm goin' for a shower.'

With that, he wanders back out again. It's only when he's getting his razor out of his office that it really hits him how she's putting herself out.

But then, he reasons with himself, police corruption is a problem for every copper and she wouldn't be the copper she is if she didn't care.