I want to start out by saying my 16-year-old SD is not a bad person by any stretch. Good grades, good boyfriend, cheerleader, etc. And for most of marriage to her mother, I have done my best to be a dad figure to her. I had no idea how to be a parent before I met my wife, and my SD helped me grow up and become a man.

For about the first 13 years of being a stepdad, everything was awesome. She called me "Dad" (and still does every now and then) and I have never considered her anything but my own daughter. My parents and family have always treated her like one of the family. She's given the same treatment by everyone for birthdays, Christmas, etc.

For the record, the wife and I have had two of our own kids.

In the last year, things have slowly gone south. A few times, they have improved, but recently, there has been no interaction between my and my SD. There's no relationship. She ignores me, and has increasingly become rude to her mother and siblings. Not coincidentally, her bio-father has been more and more involved with her life the last couple years.

Her biological father has been in and out of her life. He pays child support every so often, but has never lived up to most of his end of the court order. He's supposed to have her insured and pay for 75% of all medical expenses. He's never paid a penny in that regard. I have supported her. I have her insured (medical, dental, life). I have been the steady influence she's needed. But recently, bio-dad has become Disneyland Dad.

Out of 365 days a year, my SD sees her real father maybe 30 days. But she has said recently that he is "the most important man in her life." She once posted a tweet about a text exchange with her father, finding funny his use of the N-word (we're not black). We argued about the use of the N-word, and she took to twitter to vent about me, tweeting, "You can't be serious. This is why I don't like you."

She has also complained to my wife that I've been trying to take over for her real dad. I have never tried to replace him, and as a matter of fact, when he got frustrated with some things, he called me and offered to sign over his parental rights to me. I talked him out of it, and yes, my wife and SD were listening on the other phone to this conversation.

Last week, my SD talked with her father, and he bragged about the child support he just sent. That sparked a nasty exchange with her and my wife. My wife knits on the side, and recently used some of that income to buy a new dining room table. My SD accused my wife of spending the child support on the table. Had I been there, it would have been ugly.

My SD has not spoken to me in over a week. My wife is reluctant to do anything, and it's causing me stress. I have not been the best dad to my SD. I admit this. She holds a grudge against me in that my youngest daughter has turned into a good soccer player on a traveling team. My SD liked soccer, but we didn't know much about the world of competitive youth sports until we stumbled into the right contacts with my youngest daughter. And my job includes funny hours, which has caused me to miss some of her concerts (she's in choir) and cheer competitions.

Now, when I do go, she ignores me after the performance. Recently, I gave her use of my car so I could get the oil changed in hers. She never thanked me for getting the oil changed or for letting her use my car.

SD has no motivation in her life any more, other than school, cheer and boyfriend. Job? Please ... she has no motivation to get a job. She's talked about going out for soccer the last three years, but always comes up with an excuse. This year it was, "I don't like the people on the team," as if she didn't know the people on the team. On days she doesn't cheer, she spends the entire afternoon and evening with her boyfriend. Weekends? Same deal.

I don't know what to do any more. There's nothing left in our relationship. I have considered cutting her off. If she doesn't want me as a dad and wants nothing but her bio-father, fine. He can start doing everything that I've done through the years.