I think you might want to just deal with one thing at a time. Try to get her to move out first. Save the D talk for some other day. You might not want to use the word adultery or affair or infidelity - "dating" is probably a better word to use.
You have to be prepared for if she says no.
I disagree. "Affair" is the word to use, because that's what it is. Or, "I will no longer allow myself to live in an open marriage."
