The First and Last by John Galsworthy

To keep from any woman who loves, knowledge of her lover's mood, is as hard as to keep music from moving the heart. But when that woman has lived in suffering, and for the first time knows the comfort of love, then let the lover try as he may to disguise his heart -- no use! Yet by virtue of subtler abnegation she will often succeed in keeping it from him that she knows.

When Keith was gone the girl made no outcry, asked no questions, managed that Larry should not suspect her intuition; all that evening she acted as if she knew of nothing preparing within him, and through him, within herself.