Wow...I find your friend's (bestie) actions to be pitiful and not at all acceptable if this has become a pattern. That is not a mark of character in my book, to be repeatedly and consistently unkind, to disparage you, and/or to fob you off.
If she's not kind to you, that's completely separate to whatever she thinks or feels regarding this other person, this gent you mention.
I would be kind in letting her know you value her for who she is and want the best for her -- and that you hope that she feels the same, because that's what true friendship is. Also that you'd love to hang out with her sometime whenever's she's good with that, and to give you a ring or text anytime -- but then I would keep your distance for now. Hopefully, she will realise the value of YOU and your friendship...and if not, that's such a shame but we all do deserve to be treated with kindness and courtesy and respect...and with high regard as well, by those that are close to us.
Regarding the gent, who's to say? Maybe he really has been trying to find a way to make some conversation. You are good either way, which is good. He is a separate issue and cannot be a lame excuse for your friend to put you down. Regardless, you can be kind and friendly to him in passing as well, simply because he is a human being. If he is kind, then you can go from there in friendship or other, as applicable
If in fact turns out he is rude again, then you've invested nothing more than a little kindness and human decency
Much love & light to you
7L
__________________
Bound by conventions, people tend to reach for what is easy.
Here we must be unafraid of what is difficult.
For all living beings in nature must unfold in their particular way
and become themselves despite all opposition.
-- Rainer Maria Rilke