Like a gurl who your cousin likes. Jus plz...give your input?

Ok...yea I jus posted awhile ago about not being able to approach a gurl(if u havent answered, feel free to help me out on that post too..its calld OMG I jus need help)anyways. I like my bestfriend and one day my cousin met her. They got aquainted on myspace. then they startin chit chattn and goin on. my bestfriend likes me too but doesnt wanna "mess the relationship up". so they got close and now they fading apart..in the future would it be wrong if we got together??