I had good intentions but now I've only made things worst. Promises are important in our relationship but this one time I broke a promise I made to my bf. He has a friend who is also dating my cousin. I've always stayed out of their business but this one time when my bf told me the things his friend has been doing behind my cousin back I just felt I couldn't sit back and not find away to talk to my cousin. I went through my sister and hopefully talk to our cousin to make her aware of things. Well things turned out for the worst for my bf and I. I needed to confess to my bf and he was more upset at me bc I broke his promise. Now my cousin ended up telling her exbf how she found out about everything. Now my bf feels his loyalty to his friend is discredited. My bf is now upset at me more than ever.

Please tell me how can I make this situation better? I hoped my cousin wouldn't need to tell her exbf how she found out about everything but it didn't work out that way. I had good intentions but I've mad things worst.