"Why ?" "Because it's Sunday." "What has Sunday got to do with it?
They can't talk.

Here you are safe and sound with your friend Mrs.Burton by 9 o'clock, an intensely respectable hour even in Coombe.

What can they say ?" "But it's Sunday! You will return home, by rail, on Sunday.

Every one will know.

Your breaking of the Sabbath will be put down to careless pleasuring.