The couple is discussing marriage, which means they'll have to think about more things. It's normal to feel unsure.
The questioner should think about two things: whether to tell her boyfriend about her brother's depression and when to tell him.
My younger brother is an important family member to the questioner. It's important to value family opinions.
The questioner should ask his younger brother what he thinks. Does he want his situation to be understood by the man who may become his brother-in-law? A boy also has his pride, and he may want to show his excellence and strength, especially in front of "outsiders."
If you and your boyfriend were in each other's shoes and your partner's family was the same, would you want to know? When would you want to know?
It's not good to judge others by your standards. Try to see things from the other person's point of view.
The questioner is worried that the other person will break up with him after learning about his younger brother. This shows that the questioner values this relationship. However, a breakup is usually less damaging than a divorce.
Marriage involves emotions, values, and opinions from both parties and their families. It's about finding a balance between harmony and difference. If you can't agree on important matters before marriage, disagreements will continue after marriage. This is why you should discuss important issues before marriage.
I hope the original poster can talk with her boyfriend about her thoughts and opinions about important people and matters in her life. I also hope you can communicate sincerely and achieve harmony despite your differences. Then you can have a happy and intimate relationship based on equality, sincerity, and mutual trust and support.


Comments
I can totally understand your concerns. It's a sensitive situation, and you want to protect both your brother and your relationship. Maybe it's worth considering how sharing this might actually bring you closer to your boyfriend.
It's really tough deciding whether to share such personal information. I guess you're worried about how this news could impact your relationship. Sometimes being honest can lead to unexpected support.
Your feelings are so valid. It must be hard carrying this worry about your brother while also thinking of the future with your partner. Perhaps talking things through with your boyfriend could be a relief for you.
I see why you're hesitant to tell him. Relationships can be fragile, but hiding something this important might affect your trust in each other down the line. Opening up might help strengthen your bond.
This is such a complex issue you're facing. You have to balance honesty with concern for your brother's wellbeing. Maybe discussing it with someone neutral like a counselor could provide some clarity on what to do.