People have two types of Mahram (محرم) relations, one is by nasab (نسب) and the second is relationship through marriage. This relationship of in-laws is called Musaharat (مصاہرت), for example, father in law, mother in law, and their lineage till top, and daughter of wife, son of husband etc too. Hurmat (حرمت) with these relatives is called Hurmat e Musaharat (حرمت مصاہرت).
It is clarified that if a person marries (نکاح) a women, or makes intercourse or adultery with her, or touches her with lust without any obstruction, or sees the inner of her private part (vagina) with lust , then under few conditions Hurmat e Musaharat (حرمت مصاہرت) is proven. This means, that the Usool (اصول) of that woman (her parents, grandparents, great grandparents and so on) and Furu’ (فروع) (i.e. children, grandchildren, great grandchildren and so on) will become haram (حرام) on the man, similarly the Usool (اصول) and Furu’ (فروع) of that man will become Haram on the woman.
It is clarified that just in the way Hurmat e Musaharat (حرمت مصاہرت) is proven due to intercourse, it is also proven if touched with lust. However, other than private part (vagina) , only by looking at the remaining parts of body, Hurmat e Musaharat (حرمت مصاہرت) is not proven, but is proven only upon touching with lust. Moreover, proving upon touching is also confirmed under few conditions, which if fulfilled, the Hurmat (حرمت) is proven, and if even one of those conditions is not fulfilled, Hurmat e Musaharat (حرمت مصاہرت) is not proven.