Should I tell her I know?

[addie]

If that "friendship" has caused her to be emotionally and/or physically distant from you, has caused her to lie/omit the truth and she has come right out asking for a D, then YES she is having an emotional affair. Google emotional affairs - they are just as damaging to a M as PA. My H wouldn't admit he was having an A because there had been no physical involvement. He kept saying he had done nothing wrong yet it tore our M apart. As soon as we separated he was ready to start up a PA with OW. So yes, there definitely was an A going on.