I understand the desire to want to reach out and tell her and him how their behavior hurt you, but think about it. They already know this.
Yes, the denial is a clear indication that they are people to avoid.
Sandi is amazing - keep "Sandi's Rules" close. Most of us do and follow them. It can be difficult to fully go NC (especially at first) but then you find that you are doing great until contact, or you hear news of them etc. and it hurts again and you realize that you have peace when you just let them go and you live your life.
ME47 XH44, S28 S24 S19
8/17-BD IHS: 1/17-2/19 D FILED (ME): 7/19 D FINAL: 10/20 M23 T25 OW CONFIRMED: 01/21
Do not let your hearts be troubled and do not be afraid.