Are you 18 years old? It should be a family education problem. If you are siblings and have the same educational environment, your boyfriend will think you are making a mountain out of a molehill. Your boyfriend's tutor also needs to be considered. Or maybe you overreacted at that time, causing your boyfriend to lose face in front of his sister. Now that things have happened, we should check whether there is anything at home. Look at your boyfriend's attitude towards this matter. At that time, both sides were very excited before they quarreled. Now that the quarrel is over, it depends on what he does. Let's observe his character. If you feel sincere, you can also tell her that you were excited and didn't want to make a mountain out of a molehill. It's me. I did it. How to do it is up to you.