Hi. I'm new to this, and think maybe I just need to rant, but also just want to know that my wife and I aren't alone in this, and perhaps get some helpful perspective from others who have been where we are standing.

My wife and I got married last year, second marraige for both of us, our first ones ended in both of us being abandoned and being left to be the sole parents of our indidual children for a some years. We felt, and feel so blessed to have met, and have the same core values and parenting style, as well as falling madly in love with each other. In the process of all of that the absent bio parents of our respective child both started expressing interest in their children.

Long story short, my 5 yrd step daughters bio parent lives on the other side of the country and she just came back from spending a week with him. It's been a rough two weeks with her transitioning back to our family. We had all started growing really close and a real bond was starting to form, with my step daughter starting to call me dad ( of her own choosing, I've never expected her to call me that because I felt it would put her in an unhealthy positon). But she's back and she's cold, defiant, having tantrums, and back to sucking her thumb which she hasn't done in nearly 9 months.

Just this morning it came out that her bio dad was filling her head with poison while she was with him. Telling her things like my son and I aren't really her family, and it step dads and step brothers don't mean as much as real ones do. That I won't love her as much as I love my son because step parents can't do that. Relationships don't last so I probably won't be part of her life for too long. 

I took some time to hug her ( which she let me do) and reassure her that I love her immensly ( which I do) and nothing is going to change that. I also talked to her and my son about the idea of a blended family, comparing that to a smoothie, fruit from one family and yogurt from another mixed together into something healthy and delcious. 

I know that sounds like it's all good now, but it's not, it's still there, she's still got these thoughts in her head and I know that his guy is going to be putting this toxic thought pattern in her head whenever he gets the chance, and he's not the kind to admit that he's doing something wrong, he's always right even when he's not and he knows more about everything than everyone because he has alot of education. What can we do? Does anyone have any tips, experience, or cheat codes they'd care to share?