Deke Shu did keep his promise to let Jamie go, but he would not force the girl if Jamie wanted to stay in this house. Jamie's mother persuaded Deke to order his men to expel Jamie by force, which she would have to pay in return again.
The man had sent his men to expel Jamie by force, but he did not hide this order from his son. He knew Lawrence had been eyeing young Jamie for a long time but held back because Deke was so true to what he said.
As long as Jamie was in this house, no one, not even his children, would touch that girl. Even though he loves his son dearly and will let him do whatever he wants, Deke still warns him not to touch Jamie openly.
That's why he often sent Lawrence out of town or abroad so that his son could vent his lust on the women he meets out there.