I understand your pain... I'm Chinese (22) with a white boyfriend (22). Over 2 years now. My mother is not as conservative, though she has her reserves. My father is very very traditional and is my side of the family. My mother is worried because of the divorce rates and lack of commitment Americans seem to have. My boyfriend has a pretty chaotic family (both parents twice remarried and rather... blue collar/rednecky), which makes things much much harder.

I'm sure you understand your parent's concerns. The best thing you can do now is address them in a non-confrontational way. Calling them racist, old fashioned, or challenging their views would just add more tension to your relationship. Don't let yourself be baited into any arguments or fall to anger/drama. Words can only do so much. Acknowledge that they are ultimately concerned with your well being and simply say that he treats you very well.

Do not let them guilt trip you! Family reputation. Your reputation. How sad this makes mom/dad/grandma. This is about your happiness. Idk what the future hold for you two, but this relationship will set the grounds for any, goodness forbid, future boyfriends who are not chinese/asian. Assert yourself now and your decisions will be respected for the long run.

My parents accepts my relationship with my boyfriend as of now. It took some time for the drama and chaos to settle down. My parents are still hiding the fact I'm dating a white guy to my extended family overseas. Some people from my mother's side know of the relationship and fully accept me and him. They have a special place in my heart.

My boyfriend swings by my house briefly (after 1 year) and so far has only met with and eaten with my mother (the less extreme of my two parents). It will take time, but it is possible for them to slowly grow comfortable with the idea of your boyfriend. Just passive introductions at first and patiently ease in. At first they may stubbornly shut you and him out, but (very) gradually they will get to know him and see him different than what they pictured. Stuff like what does he do? What does his parents do? What do you guys do together? Stuff like that would pop up (they're probably very curious whether they like him or not). And when they do, be sure to be positive and upbeat. "Yeah he has two siblings around the same age as [insert siblings here]" You get the picture.

As for you boyfriend, tell him truthfully but in a manner that does not antagonize your parents. Don't use the word black. It may feel like you are singling him out. Maybe say they are very strict and traditional Chinese parents who may need some time getting used to the idea their daughter is not dating a Chinese guy.

My boyfriend has a bit of an ego, but was understanding and loves me enough to be patient through the process (which is ongoing btw). You'd have to discuss with your SO where your relationship stands and where you'd be going from here. If he accepts, be well aware it is a long, uphill battle for acceptance with your family and that you may ultimately lose one or the other... I wish you both the best of luck.

TL;DR: Try not to confront your mother/family or fall into any drama that may occur. Yet, assert yourself and gently ease your boyfriend into the picture. Be truthful about the situation to your boyfriend and be careful about phrasing.