Re: love and friends...
Just because someone professes to having feeling for you doesn;t mean u r obliged to reciprocrate the same feelings. Maybe he just isn;t what ur friend wants. If the guy still wants to stick around its at his own risk, ur friend is not to be blamed. Maybe she will end up liking him, who knows but it ould be silly for the guy to hold his breath for it.
As for ur question, I guess it has happened a few times. It wouldn;t be fair to me or the guy if I married him just cos he had feelings for me where I didn;t even have an ounce.