The cousin in dreams represents the aspects in you that are similar with someone else in your waking life. Perhaps the dream suggests you to analyze more your own personality, otherwise you will never know of who you are. If you see the cousin in a dream, then it could also signify the features you are not able to see in yourself, but see in your sibling. If you have sexual feelings to your cousin, then it shows the acceptance you have made with your personality, because you agree with who you are.
Read more about dreaming of Cousins in other dream meanings interpretations.