Hello , I am A Muslim Girl aged 22 . I want to marry a guy who is already married

I am in a relation with a guy who is already married and having two child . Bt According to Muslim Marriage act , I can marry him and he also have the right to marry me ! Both of our families knows the whole situation, at initial stage she was somehow okay with it so her husband (my boyfriend) informed me that my wife is okay with the decision as it is permissible in Islam . But suddenly she started threatening me behind his husband's back . She texts me on WhatsApp saying that don't let my husband know that I have texted you ! Just go away from our life ... And on the other hand , he still wants to marry me ! Bt his wife's brother is also threating my dad that if something like that happens .. we will burn your house , etc etc ... What should I do ? I have never an event misbehaved with his wife from the very first day and even I have never spoke against her . But she is taking advantage of it and pressurizing me .. Although I have stopped talking to my boyfriend since then , bt maybe he is unaware about the whole situation . And if he is aware still he is also in a threatening condition . What to do in this situation.. ? I can't even attempt a mistake to talk to him . And I don't know what maybe going on behind his back still ...I am so worried about this situation bcos I will never let my family face any harm ! Kindly give me a brief about it ‼️