We like each other alot . But he doesnt want my bro to know ..?

okay so i like my brother friends . N my bro told me that he didnt like me . Which i thought was bullcrap . I knew he liked me . So anywayss last night we were texting realllllly late and he tells me he likes me . ! I told him i like him too . then he tells me not to tell my brother that he likes me .. Why wud he want to hide it from my brother ? & him and my brother are reallll close .