It is allowed for muslim men to do business lingerie (undergarments).

All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His Slave and Messenger.

In principle, trading in any item is lawful unless there is evidence that it is forbidden. Hence, the basic presumption is that trading in lingerie is lawful given the absence of religious evidence suggesting otherwise.

However, if the seller knows that the woman buying those clothes will use them in an unlawful way, then it is prohibited to sell her such clothes because it would constitute helping someone commit a prohibited act. Ibn Taymiyyah wrote, “If it is believed that the garments will most likely be used to help commit sin, then it is not permissible to sell them or tailor them for the one who will use them for sinful and wrongful purposes. Hence, it is disliked to sell bread and meat to one who you know will drink wine over them. It is also disliked to sell (sweet) basil to someone who is believed to use it while drinking wine or committing immorality. The same applies to any permissible thing if you know that it will be used to help commit sin.”

For more benefit, please refer to Fatwa 83049.

Allaah Knows best.