Is It Ok That My Boyfriend's Best Friend Is A Girl?

He says they have never dated, are not dating, they are not in love, they've never kissed not to talk of going the extra mile, and he isn't planning to.

But that she is his best friend. They have known each other for a very long time.


He insists he doesn’t have feelings for her and that she doesn’t have a crush on him either. That it's just that he can tell her anything, can confide in her.
She used to have the spare key to his house until I raked about it, she actually has her own boyfriend too.

But I'm kinda confused. Is this okay?