So disappointed in my best friend!!!!

It’s probably a bit difficult to write this, but about five months ago, I met someone who really hit home for me. She’s my age, 34, and we bonded during a five-day intensive training retreat where we spent nearly every waking hour talking about everything—life, our kids, just everything. I guess you could say she really got under my skin. After that, she started coming over to our house quite often. We both have children, though I happen to be in a very happy marriage while she’s currently navigating a divorce. I felt for her, so we kept talking, almost constantly. She’d call me ten times a day, and I’d do the same; we just clicked. I suppose I’m a pretty low-maintenance person—my style is simple, I don't really care much for vanity or keeping up appearances—but she is quite the opposite. She’s stunning, obviously, and she definitely knows it. She loves being the center of attention, flirting with everyone from old friends to strangers, and honestly, she has enough shoes and heels to fill a closet. She dresses quite provocatively, which I sometimes feel isn't quite right for a mother, and her language can be a bit rough, but I still care about her deeply. I accepted her exactly as she was.
...but everything just fell apart so suddenly. One day, she came over to visit us along with one of my husband’s closest longtime friends. They started an affair—well, they thought they were being discreet, but I eventually found out. She finally admitted it to me, but knowing him as a genuinely good, decent man, I just knew she wasn't right for him. We tried to warn him, telling him to keep a cool head and be careful, but he guess he just got swept up in her beauty. The thing is, she keeps talking about him to me with this heavy sense of irony, acting like she can just play him however she wants because he’s completely obsessed with her. And then, all of a sudden, our friend just stopped coming around. It's been four months now with zero contact from him, even though I still hear from her every single day, usually in short bursts. It hurts, I guess, because we’ve known him for decades, yet I’ve only known her for a few months. My husband and I realized something was off. She’s still carrying on with him while she’s technically still married, which seems pretty reckless to me. There’s no happy ending in sight here. He’s actually hoping for a future with her—she tells me all the details—but when she talks to me about him, she mostly just mocks him. I’ve told her it isn't fair and that he doesn't deserve this. I suggested she should finish her divorce before jumping into something else, rather than trying to sit on two chairs at once.
TODAY, the truth finally came out. I finally called him and told him how much it hurt that he’d gone silent on me, especially since we’ve always been such close friends; he truly is a wonderful soul. He told me that SHE had convinced him that I was the one spreading nasty rumors about him. I was absolutely livid. She lied straight to his face about things I would never say, even though she’s the one telling me things about him that I know aren't true because of how long we've known him. I didn't want to tell him the truth because I didn't want to start another fight. Honestly, part of me wanted to just walk over and slap her. My husband said he won't even step foot in our house again. She managed to drive a wedge between me and him by lying to him, and he distanced himself from us because of it. It’s just sad; we’re both so hurt. A twenty-year friendship was basically dismantled by someone we only knew for three months. Now that the dust has settled, the reality is clear: everything she said about him was the exact opposite. She’s the one obsessing over him, she's the one pursuing him, and she's clearly crazy about him, despite how she portrayed it. He finally had a moment of clarity today and told her they need to stay apart until her divorce is finalized, and she is losing it. She’s been calling me all day crying, but I know the whole story now. I don't really know how to tell her how two-faced she’s been or how much she’s disappointed me. I don't know how she could do this to our family after we opened our home and our hearts to her. I struggle to find the courage to confront her because, I guess, I just feel so sorry for her.
What should I do?

She just called me several times again... she’s clearly worked up because he finally cut her loose... and I can feel my blood starting to boil. I suppose part of me really wants to just tell her off and make her feel some shame, but I’m just not built that way. I’ve honestly never been in a situation quite like this before, and I don't really carry much malice in me; I guess I’m just a bit too naive, believing that everyone is fundamentally good and well-intentioned. It's probably time I go see a therapist or something.

Well, then you can just deal with the fallout if you refuse to stand your ground with her. I guess you don't really have any other choice.

I suppose I’ll have to say something, though I’ve never really been the type to enjoy a confrontation; I’d much prefer to handle things gracefully rather than being harsh... and even though I know she's acting out, I can't help but feel a bit of sympathy for her, I guess... she just seems quite pitiful to me right now.

I think I’ve finally hit my limit today; she called me several times just to spin these blatant lies, and I just couldn't bring myself to listen to it anymore.
I ended up being pretty blunt with her, though I suppose I might have been a bit harsh if she hadn't known better... it's sad, really, and I do feel for her. She claims she wasn't trying to hurt me, saying she just didn't know me well enough and was trying to use him to get to me, and vice versa, but he basically shut her down entirely. Now she’s spent the day crying, sending me these heartbreaking messages about how much she knows she messed up and how she understands why I'm angry. I told her straight up that she doesn't have a real friend in me, though I guess that's debatable since she never talks about anyone else. We opened our home to her—she could have had a genuine support system in us—but instead, she's managed to let everyone down. I'm not usually one for drama, but I just snapped. I know I'm being soft, too, especially with her begging for forgiveness, but I don't think I can ever truly trust her again. I'm not sure what comes next, and honestly, it's weighing on me quite heavily.

I’ve dealt with a friend just like this before. On the surface, they seem absolutely wonderful—charming, even—but then you realize who they actually are, and it’s a total shock to the system. You don't even realize what kind of things they've been saying about you behind your back or what their real motives are. Looking at your situation, we are practically in the same boat. Honestly? There isn't much choice left but to cut them out of your life. I know, it sounds harsh, and it's incredibly difficult, but people like this simply do not change. She could offer a thousand apologies, but it won't matter; she just isn't worth the heartache. Someone like that can turn your entire social circle against you in a heartbeat. It happened to me, too. I was always the one forgiving, over and over again, and I regretted it every single time. I suppose that's just my flaw; I find it nearly impossible not to give people second chances. Don't let her manipulate you or your family. She likely knew exactly what would happen once her true colors were revealed, yet she took the risk anyway. That alone is proof enough that she'd do it all over again. Take it from someone who learned this the hard way: just let her go. I truly believe you can feel how she drains your energy and saps your willpower. She radiates such negativity. Once you finally shake her off, you're going to feel like a brand-new person. Sadly, I stuck it out with someone like that for three whole years...

Thanks, though I’m feeling pretty wiped out today, I guess... He’s lying to us, and he's lying about me too. (The guy is actually our best man, my husband's closest friend.) Honestly, I’ve never felt quite this pathetic or used before... She finally saw him for who he is, but there aren't really any words to describe how someone could cook up something like this; she’s just a total schemer. I suppose our friendship isn't going to be ruined by some random person who just drifted into my life... It's sad that people like that even exist, especially since I gave her my whole heart

First rule—cut that "friend" off completely. Stop replying to her texts, ignore her calls, don't ask for explanations, and for heaven's sake, don't get dragged into some endless drama or shouting match. Just move on like she never even existed. You don't need that kind of toxic energy in your life.
As for this best friend of yours you've known for 20 years? It’s sketchy. If you guys were actually close, why did he jump straight to believing you'd talk trash about him behind his back? After two decades, shouldn't he have enough common sense to say, "Hold on, that doesn't sound like anything driftingmoose62 would ever say. Let me check with her before I blow up a 20-year friendship"? Plus, the guy is an adult—probably in his 30s—and he can make his own choices about his dating life. Don't act shocked or heartbroken if he ends up staying with her, and stay out of it. If he asks what you think, tell him. If he doesn't? Shut it and live your life.

thanks, I appreciate it
,I suppose you might be right about how things went down, since he seems pretty wrapped up in her, though maybe she just finally managed to get through to him somehow. It’s honestly hard to wrap my head around how one woman can manipulate someone like that... He told me today that he isn't going to be with us because I ended up laying out everything she had been saying about him, and he was just completely stunned by it all. She had claimed they never even slept together and that there was zero chemistry, yet he told me they've been intimate countless times. She kept telling me she couldn't stand the sight of him, while simultaneously telling him she couldn't live without him (he really walked me through every little detail today). I wouldn't be surprised if he ends up staying with her anyway, which would just mean everyone gets to laugh in his face... it's truly wild what a woman can do to a man, goodness knows...

Honestly, you’re better off just walking away from this whole mess right now. People have this habit of ditching their best friends because they refuse to face reality. They end up convinced their friends are just jealous of their relationship and trying to tear them down—kind of like how victims of domestic abuse often push away anyone who tries to tell them the truth about their partner.
You said what you needed to say, so drop it. If your friend is smart, he won't go back to her. And if he isn't? There's nothing more you can do besides pushing him even closer to her by constantly trying to prove who she really is.