What is the ruling on a man marrying another woman with the intention of satisfying his desire to listen to female sexual conversations, especially since his first wife refuses this for a religious reason, and he believes that his action is not among the major sins?

All scholars unanimously agree on the prohibition of tribadism (lesbianism) between women, considering it one of the major sins, based on the noble prophetic tradition: "Tribadism is the fornication of women amongst themselves." Some exegetes have also narrated that one of the reasons for the destruction of the women of Lot's people was their engagement in this heinous act.

Moreover, this act involves the uncovering of private parts and looking at them without necessity, and touching a private part with lust, all of which are forbidden by consensus, based on what is stated in Sahih Muslim, that the Messenger of Allah (peace be upon him) said: "No man should look at the private part of another man, and no woman should look at the private part of another woman. No man should lie with another man under one garment, and no woman should lie with another woman under one garment."

What Sheikh Al-Munajjid (may Allah preserve him) said does not mean that tribadism is permissible or a matter of dispute. The fact that tribadism does not involve penetration or a prescribed hadd punishment does not mean it is not forbidden. Many major sins do not have a prescribed hadd punishment in Islamic law, yet there is no disagreement regarding them being major sins, such as lying, backbiting, slandering, and false witness.

As for your brother listening to women discussing these abominations and describing them with stimulating language, it is Haram without disagreement, because it falls under spreading indecency among the believers and inciting and enticing to forbidden acts. Allah Almighty said: (Indeed, those who like that immorality should be spread [among] those who have believed - they will have a painful punishment in this world and the Hereafter. And Allah knows, and you do not know.)

Your brother's statement, "We commit Haram every day, so why not do this as well?" is a grave statement that implies belittling Allah, His verses, His commands, and His warnings. This is evidence of a corrupted heart. Committing forbidden acts and their widespread occurrence necessitates repentance and regret, not justification and trivialization.