ANSWER:

What kind of a family do you live in? This sounds more like a soap opera with all family members indulging in affairs and haram relationships, may Allah protect us!

As long as you both have repented and expressed remorse and cut all relationships and communications between the two of you and the girl is a practicing muslimah with correct aqeedah, go ahead and marry her because a guy doesn’t need anyone’s permission to get married except the consent of the girl’s father (wali) and let your sister cry and make drama. 

QUESTION: I want to do a nikkah with a girl with whom i have haram relationship but my sister tells my father not to marry me with that girl otherwise she’ll marry a boy which she likes but the boy she likes goes to peers and wears amulets n ol.She doesn’t let me marry she cries and pressurizes the family.I tried to make her understand but she cries loudly and says she has anxiety

Fiqh of Marriage, Pre-Marital Relations |