My boyfriend’s best friend is a girl…?

Question by LS: My boyfriend’s best friend is a girl…?
My boyfriend’s best friend is a girl… Here is the twister: They have known each other since childhood and both swear that nothing sexual has ever happened between them, but I have heard from not only his mother but his guy friends that they have caught them together on more than one occasion over the years. They are both 40 now and these sexual acts had taken place in their 20’s, while both were in separate marriages. I am much younger than him and his best friend feels threatened by me, which in turn has caused me to raise my suspicions. She is nothing to look at by any means and well I am a model who holds several degrees so I shouldn’t feel threatened but I do. She has been in the same marriage for over 22 years, but she has cheated on her husband several times, which I already don’t care for her moral character, frankly I think she is disgusting. My worry is that my boyfriend is going to propose to me, though when her husband croaks and can’t provide for her anymore she is going to run after my boyfriend / husband and I will be left in shock. Can anyone enlighten me further on this issue, especially would love an older man’s advice.

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