Advice needed

Mmmm.. that is a tricky one if you don't want to lose her as a friend. There's so much that you can only guess at from the whole history and subtle interactions, and can't be guessed at from a few lines. I suppose in my mind I usually play out the math in simple tables. If you keep her as a friend and don't tell her you're uncomfortable then eventually you resent her and lose her as a friend. If you tell her you may or may not lose her - but now there's a chance you won't lose her.

Buuuut with that said? There is another route that is much much harder for most people, and involves a lot of challenge and growth. So what *I* would do (not saying you, you are the only one who knows you) is I would talk with my partner about my fears. My partner would re-assure me (not guessing at this, I love and trust her completely and vice versa - no matter how many lovers we've each seen the other with) and would likely keep her distance from the suitor (because seeing me hurt / uncomfortable would be worse than anything she could possible gain). Not talking hypothetically, there was one suitor who made me uncomfortable and she dropped him like a bad habit. And I have had a beautiful potential (and fairly sure) playmate who disrespected my partner - didn't even cross my mind (for more than a moment while the blood readjusted in me) to do anything with that woman. Saying 'no' to temptation is much harder for poly, in a monogomous relationship there's an even greater chance he'd keep his distance or ignore the flirting.. but it just soooo comes down to the strength of your relationship, trusting each other, their current connection, her skills at seduction.. so yea, potentially harder route - easier to just talk with her up-front.

Oh, or set her up with someone to distract her :)

That doesn't sound like a very good friend, to me anyway.

I've met women like that. It's some sort of game to them and when they get the man they don't usually want him anymore. One flirted outrageously with a married man one night and when I told her his wife was very upset,she laughed and cruelly said "oh he's very nice". I asked if she really wanted him and she said she didn't and was just having fun.

distance yourself quickly.

As an update on this, my boyfriend was away a few days. The day he was back my friend rang up and asked was he back and if she could come out with us. As you can imagine, that made me feel more worried than ever. I said we needed alone time, but really I want the alone time to be all the time.
My trouble is I don't trust her. I have big trust issues. I had a previous friend try to steal a previous boyfriend of mine and when she couldn't get him she turned hateful towards me. Said I was not as pretty, slim or intelligent as her. Then she turned against me completely.
I veer between thinking this friend is trying to steal my boyfriend to thinking maybe I am just insecure myself and she just wants company, but how do I know that? She herself said she would go after any attached man she liked it makes me feel very stressed having her along.Should I raise these concerns to her?
Aside from these things I get on well with her. Can I somehow say I don't want her along and blame it on my own under confidence...because I do feel under confident in her presence. Looks wise, she is everything I am not (stunning) and I don't really understand shy she doesn't ever meet any guys who are really into her.

Cut her off she doesn't seem like a good friend and if you already know her track record there's no need to entertain her.

you my love would be better off with no friends if your depending on that bi..h

I'm all about poly but not everyone belongs in that boat. And those who Do belong in that boat focus a whoooole lot on respect, comfort of everyone involved, and clear constant communication. Doesn't sound like she is. So if you don't mind losing her as a friend then I'm sure you have plenty of other things to do with your time / people to share your time with.

Yes moonstar it is. Usually these women are stunners too and think every man fancies them and love the attention. Even if they date a single guy they constantly humiliate him by flirting with other men.

I'd still say talk with him first.. but also, do you know if she's bi? Not trying to be pervy but she may be trying to go out with both of you.. to go out with both of you. Not saying it's what's happening, you have a better read on the energy even you're together, but I have seen it happen. If that's not it I'd probably talk with my partner before anything else but again, that's me. I can't honestly remember these kinds of relationships very well so I'll let others who do give better advice

be up front and tell your friend as you call her to take a hike !

That is so horrible Hennypenny...I have know this woman to flirt with married men on a number of occasions as well ... once even got this guy's phone number. I think it's despicable.

I don't have that many friends, and I don't know what do do. Should I say something to her, or just make some excuse every time she asks to come along.

Yes she is very pretty, blond and loves make attention.