The development of contemporary sexual practices has given rise to various forms of sexual relationships that depart from the normative boundaries traditionally recognized in Islamic teachings. This phenomenon calls for a comprehensive understanding of the Qur’anic concept of sexuality to ensure that its underlying values remain relevant to the challenges of modern society. This study aims to analyze the boundaries of sexuality in the Qur’an based on Qur’an 23:5–7 and to examine their relevance to contemporary sexual practices through a maqāṣidī approach to Qur’anic exegesis. Employing a qualitative method and a library research design, this study draws primarily on the Qur’an and relevant exegetical works as its principal sources. The primary data consist of Qur’an 23:5–7 and relevant works of Qur’anic exegesis, while secondary data are derived from books, journal articles, and scholarly literature addressing sexuality in Islam, including Abdul Mustaqim’s Tafsir Maqāṣidī. The findings demonstrate that Qur’an 23:5–7 remains highly relevant to contemporary forms of sexual transgression within marriage. These verses emphasize the obligation to safeguard sexual dignity and confine sexual relations to a lawful marital bond. From the perspective of maqāṣidī exegesis, practices such as open marriage and swinging have the potential to undermine the fundamental objectives (maqāṣid) of Islamic law. Accordingly, this study underscores the importance of strengthening the understanding of Islamic sexual norms to ensure that marital relationships remain within the framework of Islamic law and that human well-being (maṣlaḥah) is preserved.