This is a very sensitive situation, and the only one who can resolve this is your boyfriend! Nobody else!
He should be very firm about your relationship and very supportive to what you are doing. Sometimes he should stand out and take the responsibility of certain decisions, even if that's your idea.
I suggest you to raise this issue very seriously to your boyfriend, and tell him that if the relationship between you and his parents remains like this, the only choice you have is to break up with him. Ask him what he is willing to do, and take action according to his response.
If he is willing to protect you and face his parents, then you may go on together to see how.
If he is too weak on this and you still have to confront his dad or mum personally, then my suggestion is to break up and move on.
A girl's golden time is so short, don't waste it on someone whose family don't get along well with you. I saw live examples in which the girl misses the whole forest when she finally get down from that tree...
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