It's challenging to determine the exact reason for your boyfriend's sudden change in behavior without more context and information about your relationship. However, there are a few possible explanations for his reaction:
Jealousy: Your boyfriend might have felt jealous or insecure when you mentioned another guy you were talking to. He might perceive this as a potential threat to your relationship, leading to feelings of discomfort or bother.
Insecurity: If your boyfriend has pre-existing insecurities about himself or your relationship, hearing about another guy could trigger those insecurities and cause him to feel bothered.
Miscommunication: It's possible that your boyfriend misinterpreted your intention or the context of the conversation. He might have thought that you were developing feelings for the other guy or that you were trying to make him jealous.
Emotional sensitivity: Your boyfriend could be going through a difficult time emotionally, and the mention of another guy might have hit a nerve or brought up unresolved issues.
Past experiences: If your boyfriend has had negative experiences in past relationships or has been hurt before, discussing another guy might have reminded him of those situations.
Lack of trust: If there are trust issues in your relationship, your boyfriend might have reacted strongly because he was unsure of your intentions or felt that you were hiding something.
In any case, the best approach is to talk openly and honestly with your boyfriend when he is ready to discuss the matter. Choose a calm and private setting where both of you can share your feelings and concerns without distractions. Be empathetic and try to understand his perspective, while also expressing your own feelings and intentions.
Communication is key in any relationship, and addressing concerns early on can prevent misunderstandings and strengthen your bond. Remember that relationships require effort from both partners to maintain understanding, trust, and a healthy emotional connection.