Here are some suggestions:
1. Stay calm and respectful: Although you may feel confused or surprised, stay calm and respectful. Don't overreact, listen to my cousin's feelings and thoughts patiently.
2. Frank communication: communicate frankly with my cousin to understand his feelings and thoughts. Try to express your views and feelings in a peaceful, rational and mature way, and let him know that you value his feelings.
3. Emphasize age and maturity: As an elder, you need to let your cousin know that this feeling is not suitable for his age and emotional maturity. You can discuss with him the physical and psychological development and the relationship between these developments and emotions.
4. Establish a healthy family relationship: Although your cousin expressed this feeling, you still hope that he can establish a healthy and normal family relationship with you. Try to maintain natural and normal interaction and avoid causing him more misunderstandings or fantasies.
5. Ask for help: If you feel very confused or unable to handle this problem, you can ask for professional help, such as a psychological counselor or a family therapist. They can provide you with more specific advice and support.
The most important thing is to deal with this problem in a healthy and rational way, help my cousin understand his feelings and protect his physical and mental health.