It means he wants someone else but is flirting with you as a second resort if the person he likes doesnt like him back
Could you be more confused? You like this boy so you should tell him. If you mean that you like your friend who likes someone else, and that someone else does not like him, i wish i knew. I think it depends on who the person is that you like. but one thing is (sadly) true, if he does end up with you, will you ever be able to be sure that he likes you for YOU, and not as a replacement for whoever?
just ignore him
If the other person strongly dislikes the person, then they should get over it and find someone else.
The guy is over the other person and likes you!
You let them down easy by telling them you are interested in someone else.
Let them know how you feel before it's too late and they are taken.
Get noticed. Try out for things that person likes but not all that person will think that something is weird. Don't act desperate and seem interesting good interesting.
Spend some time with that person alone without your friend. If that doesn't work, move on.
Try talking to them about your feelings for someone else and look out for their reaction 9/10 is obvious that the person likes you or not.
find someone else to like
Leave him alone and back off. He likes someone else.