Change in behavior

Going through a separation. What led me to this point was the other person being emotionally manipulative, hiding mental health issues, and attempting to meet up with a member of the opposite sex. No chance of reconciliation but still going through the process. They started talking to the same person again. The person blew them off in the past. When this happened there was a noticeable shift in their behavior. During our separation I noticed this same shift in behavior and a mutual friend confirmed that person blew them off. Since then they have acted a lot differently, they are calling to talk more, every conversation is monotone and telling me they love me every time they see me. A friend said they are showing regret by these actions.

I have no intent of reconciling, but I do want this process done with. We are still living in the same house that is in the process of being sold. I can't leave until the custody agreement is completed because it would be considered abandoning the children.

Just wanted to ask the group, is this the other person showing regret, and if so should I be worried about them trying to do anything to try and get back together?