Ongoing affair, D papers filed, advice wanted

[SirPrizeMe]

W started a PA in May 2006, it continues to this day. D papers filed November 27, 2007. She is still seeing OM.

He is blowing up. Two DUI arrests in a single week. I spoek to OM's stbxW and learned he is dating 2 other women, at the same time as my wife.

First question:
how do I get this information to W? Is she aware that he is "unfaithful" to her?

Advice please!