It is quite likely a physical attraction alone. Regardless of being a cousin and setting aside moral notions, physical relation before marriage comes with a certain risk, especially for the girl. Romance and physical attraction wears off as swiftly as it comes, especially after physical involvement. My suggestion would be to wait and not concede to these feelings. Turn your mind towards creative activities rather than rush into crossing a line of no-return.Â
Affectionately,
Alok Da