Question Summary:
Can a married women have relations with other than his husband, can she have sex with a person who is INTO husband’s blood relations.

Question Detail:

Can a married women have intercourse other than his husband, can she have sex with a person who is INTO husband's blood relations. 

Answer :

In the name of Allah, Most Gracious, Most Merciful
Assalaamu `alaykum waRahmatullahi Wabarakatuh
A married woman can have intercourse only with her husband. It is haram for a married woman to have intercourse with any other person even though he is the husband’s relative. That will be zina and a major sin. In an Islamic country, such a sin in punishable by death.
And Allah knows best
Wassalam
Mufti Ebrahim Desai
Darul Iftaa, Madrassah In'aamiyyah