What do I do if my best friend....?

...is obsessed with me ? She gets soo jealous when I hang out with someone else . She's paranoid that someones going to "steal me" from her. Its getting annoying. She jokes about js being lesbians , its not funny. One time I said she was acting retarded and she bawled her eyes out for hours. It's annoying. I have lots of other friends , who aren't crazy(: