She might be a little too proud

I totally get it....I have this friend too who is bi and every fucking time in front of fucking everybody she just had to mention it..and people here are so close-minded.And the problem with those people is that sometimes they can easily out you to everyone without even doing it on purpose.When I told her,everytime she was asked by someone if I'm gay she just wouldn't say no(eventhough i told her to), she would just say "I don't know,I'm not sure." and that doesn't help much.
I guess you could talk to her the next time she mentions her sexuality,why she does that so often.Maybe that way she will understand that it is too much and it has to be kept to a minimum.this way you don't come out to her and you solve the problem without taking risks.

 

I've been in a situation like yours, too. I have a very open gay friend of a friend that I end up hanging out with sometimes and he never shuts up about it which really got on my nerves when I was struggling with my identity, and it still does get irritating sometimes because I'm not out and he is. In my case, it was sometimes too much and I'd have to change the subject or have to "go to the bathroom" and walk away for a bit. But with you it sounds like you're a lot closer with your pansexual friend. If you really don't want to come out, just try changing the subject when stuff comes up or, like Ren said, confront her about bringing it up so much. I think everyone's been in a situation like this at some point (*hug*)

 

I have a Bi friend that did that. Lmao
She pretty much got everyone passed off at her. She's stopped since then.