This is not a problem,
yet.
If the both of you are mature enough, that will be may the best man
wins.
If not, will be no, she's mine, no, not yours...blah blah.
Anyway, this is also not up to you both to decide, depends on the
girl's feelings lo. The only thing you can do is to hope.
Go for it, love is meant to get, not to wait.
Friendship is meant for I'm with you no matter what.
If you really cherish your friend, don't break it, a true friend
beats zillion of any other friends.
So, in time, the both of you sit down on a bar counter, chatting
about the past, laughing about the time when the both of you fought
over the same girl.
The best would be both love and friendship obtained.
Lastly, if you really didn't make it, be a Man,
do the right thing, don't fuss over it, Love is not to be forced but
to be chosen.