What is the criterion for lying between spouses?

Question:
What is the criterion for a wife lying to her husband, or a husband lying to his wife?

Answer:
As you heard, meaning in matters concerning them, it does not harm other people. For example: "I will give you this," or "I will do this for you," and she says, "Rejoice in good, I will not contradict you, I will not disobey your command, I will not do this, I will not do that," so she pleases him.
Q: Okay, if a husband promises his wife that he will buy her something and then breaks his promise?
A: That is lying, or if he promised her and then broke his promise; it is the same.
Q: Meaning: there is nothing wrong with this?
A: There is nothing wrong with it between them specifically. It does not concern other people.
Q: Some scholars classified a man lying to his wife, and vice versa, as tawriyah (euphemism)?
A: No, there is nothing wrong with explicit lying, and what harm is there between them? For example, she says, "Look for a house other than this one," and he says to her, "We will buy a better house than this, give me this, give me that piece of clothing," and he says, "If Allah wills, rejoice, just give me time and I will buy it, if Allah wills," and so on, while he intends not to do anything.
Q: Is it like stalling?
A: No, it is not stalling. He lies that he will do this thing when he is not going to do it, just so she thinks he will do it; so that she is pleased and the animosity between them disappears in the present time.