Sam had been caught by Susan simply because he had seen Susan before he saw her.
All that would be necessary was a good chance at him, and he would never look at Susan again.

He had been in the East, where the admired type was her own--refined, ladylike, the woman of the dainty appearance and manners and tastes.

A brief undisturbed exposure to her charms and Susan would seem coarse and countrified to him.

There was no denying that Susan had style, but it was fully effective only when applied to a sunny fairy-like beauty such as hers.
But at midday, when Susan came in with Warham, Ruth's jealousy opened all her inward-bleeding wounds again.

Susan's merry eyes, her laughing mouth, her funny way of saying even commonplace things--how could quiet, unobtrusive, ladylike charms such as Ruth's have a chance if Susan were about?
She waited, silent and anxious, while her mother was having the talk with her father in the sitting-room.