Wa `alaykum as-Salamu wa Rahmatullahi wa Barakatuh.

 

In the Name of Allah, Most Gracious, Most Merciful.

 

All praise and thanks are due to Allah, and peace and blessings be upon His Messenger.

 

If a wife has evidence to believe that her husband is promiscuous, then she is justified in avoiding intimacy with him, especially if she fears STD. She has a right to protect herself. Furthermore, a husband who is adulterous and persists in it is guilty of infidelity and breach of trust. These are even sufficient grounds for divorce.

 

Allah Almighty knows best.