Direct communication: If you want to discuss this issue with your ex-boyfriend, you can communicate with him directly. You can text or call, but make sure your tone and wording are calm and respectful. In communication, you can ask him why he speaks ill of you behind your back, listen to his response and explanation, and express your feelings and opinions.
Don't be too entangled: whether your ex-boyfriend responds or not, you should not be too entangled or addicted to this unpleasant emotion. This is a common phenomenon after breaking up. You can learn from it and move on.
Reflect on yourself: When considering the interaction with ex-boyfriend, you should also reflect on whether you have any improper behavior or remarks, and whether you have left a bad impression on others. Sometimes, we also need to find reasons from ourselves and try to improve our words and deeds.
Seek support: If you feel depressed or unable to handle this situation, you can seek the help and support of friends, family members or professional psychological counselors. They can give you different opinions and suggestions to help you deal with this problem better.
In short, communication with ex-boyfriends requires calmness, respect and understanding. Although he may disappoint you and confuse you, don't be too emotional and entangled. Express your feelings and opinions through direct communication, reflect on your words and deeds, and seek support and suggestions to deal with this situation.