Thanks for your query. It could be infatuation that is normal for this age which would require sorting out the issue with help of a few common friends or the person concerned (your boyfriend) himself. However, if other facts you report are true like your friend wrongly claiming your boy-friend as her classmate and so on, it could mean underlying psychotic illness like erotomania (persistent delusional disorder
) which i do not expect to be in this case. Hence i would suggest you try to sort out the same at the level of your friends initially and seek psychiatric evaluation if required later on.
Dr Sundar Gnanavel