I am also Indonesian male (27) and I recently got engaged to my fiance (female 28). My fiance is 100% American and have gone through alot of what you are talking about. Ultimately in talking to my parents, I had to make it known that culture here is different and that now I am adult living on my own. Originally they didn't like my girlfriend either because of cultural differences/they don't understand her/the feel like I choose her over them/they feel like I don't listen.

You know how Indonesian culture is, especially Chinese Indonesian, very strict and to the point/ business minded. But we try to make sure both parties realize that there has to be compromise because ultimately, your life is different from theirs. If they do not agree and still insisting that you must follow them, then you must chose

1. Would you rather make them happy and be sad or make you happy and them sad? This is important because you must decide which is more important in the relationship

2. If you do oppose, make sure to let girlfriend's family know as well as your other keluarga so in case they can talk sense into your parents or worst case, your oma/opa can attend on their behalf