So I have been debating seeking advice about this. But its eating me up and I am really trying to be a supportive friend and don't fully know how to be in this situation. Struggling to find the words.

I will try to make this long story short.
Friday evening I received a random msg on FB from someone (a women) I didn't know. I accepted it because it said we had a mutual friend. My best friends Husband.
Well, life got busy, she moved away, we don't talk often. But its still a very close friend. I met her when we both were in the Military. I am her oldest sons Godmother. We spent every Holiday together. Were in each others wedding....ect...

Any who, this gal start talking to me and basically comes out to say she has been "talking" to my friends husband and they were going to meet to start dating but she started to catch things here and there and suspected he was still married (apparently he claimed he was in the process of divorcing)

I had to call her. It was terrible. I felt sick. I was shaking. I didn't know what to say. 4.5 hrs of being on and off the phone it was all unwinding. I was watching my best friends world and marriage fall apart. Now her husband had just gone on a trip with all the kids and to families. She stayed behind because she had work.
She said its been a rough year but she didn't suspect THIS.

My heart is so broken. I thought her husband was the most amazing guy for her. He loved her so deeply and was not shy to let the whole world know how much he adored her. I never, EVER imagined him capable of this.
My heart just hurts for her.
What can I say? What can I DO from far away?

*also- neither of us have heard of this app (is that a sign we are getting old?) but apparently she met him on Tinder?!?!
Has anyone heard of it? Is it like a "hook up" app or something.