Best friend is having an affair with a married man
Edit: Since I got accused of being AI, btw this is a throw-away account.
My best friend (28F), let's call her Sarah, is a teacher and started talking to someone at work. At first it was really just as friends, but after talking for a year, they started to develop feelings for each other. Sarah told me about it before anything happened. I told her that she could not go any further with him. I told her that the best thing to do was to keep her distance from now on. I understood that that was a hard thing to do, because letting someone go that you really have feelings for, is really hard. But in my opinion, he had to figure out what he wanted: Working on his marriage or ending it to start something with her. That is the correct thing to do, in my opinion at least... About 2 months later, she told me they had gone further. I thought maybe they just kissed once, and they were now planning to fix it: tell his wife and work it out. When I asked how far, she told me they had had sex, several times. Apparently they really thought this through and they feel very guilty, but they keep on having the affair, because even though they know it's wrong and feel guilty, they are also really happy when they are together.
In my opinion, they should stop this, he should tell his wife what happened (cause she deserves to know) and he should figure out what he wants. What he is doing now is the temporary easy solution: make sure his wife doesn't know and figure it out while being with both women.
I'm actually not okay with it... I've talked to her about it already. She knows it's wrong, but keeps doing it anyway. It's been going on for 3 months now.
I understand that you can have feelings for someone outside of your marriage, I really do. But then you should come clean to your spouse and work on your relationship, or end it if it can't be fixed. That would be the right thing to do.
I have a hard time with this. I don't know what to do... I can't do anything more than having the conversation we already had, where I told her how wrong it was.
Is there anyone who has been in this situation, as the friend (me) or as Sarah?
What did you do?
Do you think this is okay in some way? Are there people who do cheat like this and eventually marry that person and live long happy long lives together? Does that make it okay?
I'm torn between that fact that she may have found the person that will be the one for her, and that it is really not that easy to stop this, and the fact that it's just wrong and they should have handled it differently.
I want to be there for her as a friend, but I'm just so not okay with what's happening that I don't know what I will do in the future when she eventually stays with him and has kids with him.
I just want some advice on what to do and what other people think of this situation.