Best friend of 15 years called me a desperate homewrecker. Thinking If I should let this friendship go or try to talk it out

Has she made other comments in other occasions that have made you feel this way?

Sounds like she’s projecting.

Is she always judgemental, or was this a one-off statement?

It merits calling out and having a discussion, but I wouldn’t write off the friendship.

That said, ensure things are very platonic in your outing with your friend.

I mean, for a best friend of 15 years, I wouldn’t block her over a dumb comment. But I would make her explain herself.
I’d probably hit her back with a
“Well that was very uncalled for”
Or
“Well that was rude”
And see what happens?

A comedy show then reservations to dinner afterwards? Her reaction was rude but it sounds like there might be more to the story.. unless she’s usually this irrational

As her best friend for 15 years I would confront her about it she obviously knows you well so it is weird for her to say that. Also probably unpopular opinion and like you said you have no intention of doing anything and only see him as a friend but are you sure he does and is his wife ok with you going with him for his birthday instead of his guy friend

Some friendships have to be outgrown.

If she really cared about you and is worried about your heart getting broken, this judging by her comments, she could warn you in a more respectful, caring way. Otherwise she is just taking any chance she gets to put you down.

To me it sounds like she has other issues. Either she is bitter or feels envy for anything going on in your life.

This is so cruel of her. Why would she ever go there if she knows how much you respect him? Idk I would personally let the friendship go. She sounds like drama.

i’m thinking if he’s hiding all of this from his wife. then she would be hurt for sure.

I would just avoid this subject w her don’t bring it up anymore and go enjoy yourself but don’t mention you bought a dress or went or what you are that night- nothing. I’d go but pretend it didn’t happen when I’m around her and just move on. What concerns me is you said “she’s always thrown jabs but in the last few years they have been plain cruel” ….so maybe according to that you should think of letting her go if she’s gonna make comments in the future as well since she’s made comments in the past.

Cut the frenemie and protect your peace. She sounds like she's like this generally digging you often!

Some people don't understand genuinely female/male friendships which are absolutely possible.
The only ick here is he is not need to look after the wife after car accident etc but that's not just you, that's on him if it's not appropriate. But I assume the wife has said go and enjoy with your friend.