Wa `alaykum As-Salamu wa Rahmatullahi wa Barakatuh

 

From a legal perspective, the son is not responsible for the evil doings of his father. Allah has confirmed that a soul does not bear the sin of another soul. Even a Muslim can accept the invitation of someone whose earnings are unlawful because the Prophet accepted the invitation of the Jewish lady who invited him to eat from a banquet that she has prepared for him and she has put poison therein, though most of Jews treated in interest.

 

I wish you can approach your parents in an open minded discussion and to discuss the issue with them after telling them that you are not going to do anything against their will.

 

If they insist on their opinion, you should accept and respect their opinion since they may have a stronger reason for refusal but you do not know. Respecting their will is a good blessing and Allah will definitely compensate you with a better choice.

 

Almighty Allah knows best.