Hi fellow brazilian :D
Well, I understand how you feel, I had to go thru the same with my mom when I was younger, still handle that even tho now I am a grow ass woman with kids and she teorically shouldn't give me that kind of speech anymore.
He has the right to dislike the songs, however he shouldn't criticize you for liking them. People should be open to different kinds of art and music is art too. My mom always said to me a lot of things cause I am fascinated about asian cultures since I was little, even not having much info cause there was no internet I would still watch documentaries and look for different recipes from other countries. When I started to get older she kept complaining and dissing on my preferences, same she did with heavy metal when I was in a fase I would travel and go to concerts with friends a lot.
What I started telling her and still do is first thing, I grew up watching european movies wich helped me a lot to not only be aware of the american industry and that led me to try movies from many different countries, music also happens that way. Before I met kpop I used to fall in love with songs I heard in animes and jdramas, things are always connected, you know more stuff cause you curious and that's good. He might preffer american music, but he needs to understand music is also related to mood and preferences, him judging what you should enjoy is kind of unfair.
There's something you need to understand, even growing older won't change who you are and if you trully enjoy that most likely will be for life, like me that now watch animes and listen to kpop with my kids. I still hear a lot of crap from family cause the way I look ( total boring ordinary mom) doesn't portrait my unconventional personality, but is not my problem to fufill their expectations about someone totally "crazy" cause like that stuff. People will always judge you need to work on that with yourself to first, learn how to respond sometimes cause I don't really admit people feeling superior to me cause they thing they like better stuff. Second, need to learn not to loose your temper cause of that, isn't worth, so be smart replying. And third, filter better the people you will keep around you ( except parents, you can't avoid them lol) cause there are always those that know how to push the wrong buttoms without respecting differences,
About being racist, I wouldn't say that, but we don't have much exposure to any asian culture here in Brazil, we have a huge japanese colony but in the media we hardly see our asians having space to act or sing. So people still treat asian culture as something we only see there in between them, they forget is a big part of here too specially in São Paulo and Parana. He ain't much different from most guys here, even my husband that watch animes still resist to music and movies from asian artists. Honestly is dumb, but we can't force them. This is just something that we need to change slowly, demand to see a more "mixed" tv that portrait better our racial reality, we are a bit of everything but we mostly see caucasians, this is all connected cause create perspective for many. Older people have a really hard time changing, so you will do better if you change the way you handle that to be easier and hopefully he gets more understanding with time. Just remember to point to him, how many wonderfull things we can find in other cultures, not just ours and specially not just listening to american song, world is bigger than america.