Hey UberD,
Now that I've given her "permission"
I know this has been debated to death, but I'd like to add my 2cts worth.
This statement was not that you gave her permission to cheat, but it was giving her a choice to 'do the right thing'..... obviously, she did not 'do the right thing' by you and your family, but for herself.
As to pics of her sister, well.... okay smack your hand, and never do something like that again. It was not right, but it has been done, and (hopefully) you have learned not to do it again.
There were signs like when I gave her the ultimatum on saturday that if she went to maine I wanted her to "leave" (I didn't specify enough what that meant originally...)
Stop playing games. Stop they cryptic ultimatums. They will hurt you on the long run. Be clear and concise as you cannot afford to be grey. It cause an already dangerous situation to be even more dangerous, as both parties will be second guessing what each other is thinking.
I had said this morning that I was forgiving her and releasing her and really hopeful for our future
Forgiveness that is easily given is not true forgiveness. You only set yourself up for resentment on the long run, because you will not forgive yourself for giving in so fast.
she talks about how she's not on birth control so get condoms
This is a joke. Cheaters hardly ever use condoms. Tell your WW not to waste her money (better if delivered dripping with sarcasm).
The animosity has been simmering - she said when she revealed her "feelings' that it's been 5 years she has felt disconnected and resentment (drinking, my lack of caring, etc.).
Again, typical cheater behaviour, re-writing of marital history. Yes, there probably were issues in the M before, but if she had talked about it, they could have been resolved.
As to the calendar invite, she is goading you into a fight. She knows she is disrespecting you, and wants you to lash out. This will give her ammunition to say that you are 'controlling' her, giving her more reason to go have a sex-fest with her boyfriend.
In summary, be clear in your communication to your WW. Stop waffling. You either want her to know what you are saying, or you don't. If you don't then continue being vague.
Take control of your life, and that of your children. They will need you to be stable, safe, dependable, healthy. As such, go on the planned family outings, and be as normal as you can with your kids. This does not mean that you have to hug and kiss your WW in front of them, just do not argue/disagree in front of them.
The 180 does not mean that you need to be mean to your WW, but it is a way to start your detachment from her, for yourself. This is to protect yourself, and by extension, your kids. Conduct yourself in a 'profesional' manner. No need to talk about personal issues (except if it involves the kids). No need to say 'Hi, WW, did you have a good day?'. A simple 'Hi' will suffice.