Most Helpful Guy
This is messy, as adults all 3 parties need to grow up and stop with the childish immaturity, their are children involved! Put the personal BS aside.
On a side to you directly, can you really be surprised by this? You separate from your husband, he jumps to your “best friend” then you take him back years later knowing he has a permanent connection with his ex... I’m mostly concerned with your mindset, confidence, and self value to allow such a cluster fuck into your life. Do you not think you deserve better than this toxic situation that you enabled?