She could feel Paul being drawn away by this girl.

And she did not care for Miriam.

"She is one of those who will want to suck a man's soul out till he has none of his own left," she said to herself; "and he is just such a gaby as to let himself be absorbed.

She will never let him become a man; she never will." So, while he was away with Miriam, Mrs.Morel grew more and more worked up.
She glanced at the clock and said, coldly and rather tired: "You have been far enough to-night." His soul, warm and exposed from contact with the girl, shrank.
"You must have been right home with her," his mother continued.
He would not answer.

Mrs.Morel, looking at him quickly, saw his hair was damp on his forehead with haste, saw him frowning in his heavy fashion, resentfully.
"She must be wonderfully fascinating, that you can't get away from her, but must go trailing eight miles at this time of night." He was hurt between the past glamour with Miriam and the knowledge that his mother fretted.