Is a husband's receiving flirtatious calls from girls or his direct communication with them considered marital infidelity, and what is the ruling of Islamic law concerning it?

Islam has erected a strong barrier between men and unrelated women to prevent temptation, and the Prophet, peace and blessings be upon him, warned against the temptation of women. Unnecessary conversations between genders, especially if they involve flirtation, are among the greatest causes of temptation and are reprehensible; as Allah Almighty says: ﴿So do not be soft in speech [to men], lest he in whose heart is disease should covet, but speak with appropriate speech.﴾ As for the term "marital infidelity," it is not mentioned in Islamic law, and it suffices to know that this act is forbidden. A wife must pay attention to her adornment for her husband so that he does not look at others.