Jar, you are allowing your emotions to lead you way too much. I know this all sucks really badly, but you keep waffling back & forth on how you are acting & treating her and you need to stop that or she is going to stay just as confused as she was before and still is.
I agree, I don't like it that the OM is around your kids at all. That is something you will need to address, however, if they all know each other already, it's not like she's bringing in some new guy that they don't know.
I truly think you need to go DARK!!!! DARK, jar, DARK. Contact her about the D's and that is it. Be loving, supportive, etc. and don't allow her to pull you into arguments constantly. That's just justifying her in her supposed feelings about you and how she is allowing herself to see your M in the past.
Me: 38 H: 35 S4, S5, S10 Bomb 01/07 Wanted D - nothing would change his mind Numerous A's prior to D bomb; EA prior/during D bomb Piecing 04/07 Deployed for a year 05/07 Still Piecing 2010 M 11 yrs 05/10