Well I am gonna try to answer to best of my knowledge. Like intelligent guy said hindu religion anusaar 7 pusta samma bihewaari chaldaina. But as far as usko mamaghar being Adhikari, that doesn't mean you are by any means related. If you are than I think you can understand why it might be considered wrong. Now see kati le eutai gotra bhaye ni bihe hundaina bhancha tara that rule differs from community to community in Nepal. After all, eutai chad manaune ra puja garne tarika nai nepal ko farak farak part ma farak nai cha. So is the rules regarding marriage.

As far as talking to your parents, thats all on you. You are the one who is gonna have to spend your life
Well I don't know if this helps, good luck.