recently I have been joking with my best friend that I was gay and she was going along with it and we say that she is gay too So do you think that I should just tell her?
It sounds like she is okay with the idea...although, does she have any other friends that are gay? Or, do you know her stances on politics? I guess the main question is, are you sure she's okay with it? And, if you think she is, if you're ready you could tell her.
That's nice to have a friend that's like that. I think you should ease her into it though, like I did with my 'friend'. We've been talking for a while and then I just told her "hey I might swing the other guy. I have a crush on 'that' guy *and guy passes by*" And she actually asked me if she can date the guy. But that's beside the point! Well good luck in telling your friend! No harm trying!