Hurt..."PERHAPS" with 13 years together, your history and two young kids, given HER actions YOU should be done with the relationship and moving on. Married or not, I believe the advice you receive here is valid and applicable to your sitch. Yes there are the legal and spiritual aspects to marriage that are not in your sitch, but giving your love/trust to your partner and being blatantly disrespected/abused by a mother with two young children acting like girls gone wild...you get where I'm going with this.
If I were you I would abstract away your concerns about married/not married as it does not matter here. You deserve a loving reciprocal relationship built on trust AND your children deserve loving parents who place them first above all else. You sound better, more stabilized and focusing on your kids and your GAL. Keep going!
You need to change your perspective. It's not is she done with you, but rather should YOU be done with her? I will almost guarantee that the toughest part for you in that thought process is the impact on your children and trust me I completely get that, but if she is as wayward as she is and determined to be with OM, you need to get out of that abusive relationship first in order to be the best father you can be for your children. And don't kid yourself, she IS emotionally abusing you by her actions.
Praying for you buddy. Ain't no way else to handle it, but right straight on through it...keep going... you are not alone.
