My ex and me had a kid at 18. That followed two more little girls over the years. I wasn't all ways the best person to her, I hung out a lot, I cheated, but we always managed to come together. We finally split five years ago we continued to sleep together off and on over the years. Now here recently we started talking about maybe getting back together well come to find out she had been seeing somebody while we talked of hooking back up. Now in one week my kids have went from this is mom’s friend to him spending the night with the kids and playing dad to my kids. My first thought is to take the kids because she hasn't known him long. Should I be upset about her behavior are should I just trust her judgment

I think you have some real issues of not being able to let go. Having pity sex is bad enough, but now, you are having problems with her having a boy friend? As long as he is not doing drugs, a child molester, or abusive what is the problem? Maybe you two finally need to sit down together and figure out how your life as divorced parents of your children needs to happen for the best interest of the children. Get a custody order in place and work together to raise your children in a loving atmosphere.

If you were never married to her, and don't live in Arizona or California, you have NO legal rights to the children.

You will need to file for parenting rights. In this case I would recommend Bird Nest Custody, whereby the children stay in one home and each of you live with them for three weeks than switch. No dating or overnight guests while in the home.

It’s a form of access or custody where the children stay in the former family residence and it is the parents who rotate in and out separately and on a negotiated schedule.

The children simply live at "home" and the separated or divorced parents take turns living with them there, but never at the same time.

The core element of this arrangement is that each parent maintains a separate residence where they live when it is not their turn at the "bird's nest". When one parent arrives for his/her designated time, the other vacates right away, so as to minimize or eliminate the presence of both at the same time.

At times, bird's nest access can be coupled with specified access with the other parent say, for example, for dinner one night a week.

Sometimes, this form of access or custody will end when the youngest child reaches the age of majority at which time, one parent either buys the other out of their interest, if any, in the former family residence, or it is sold and the proceeds divided pursuant to the matrimonial property regime or separation agreement.

The arrangement can be expensive as it generally requires that three separate residences be maintained, the "nest" and a separate residence for each parent.

The concept is somewhat novel and appears to have as its origin a Virginia case Lamont v Lamont.
In Canada, Greenough v Greenough was a ground-breaker case in that the Court implemented a bird's nest custody order even though it had not been asked for by either party. Justice Quinn, in Greenough stated:

"In Lamont ... the court made a bird’s nest custody arrangement in which the children (aged 3 and 5 years) remained in the home, with the mother staying in the home during the week and the father on the weekend. I think that the benefits of a bird’s nest order are best achieved where the children are able to stay in the matrimonial home, particularly if it has been the only residence that they have known....

"Time and time again I have seen cases (and this is one) where the children are being treated as Frisbees. In general, parents do not seem to appreciate the gross disruption to which children are subjected where one of the parents has frequent access. In this regard, I do not believe there must be evidence that the children are suffering before the court is free to act. To me, it is a matter of common sense. At the risk of falling prey to simplistic generalities, I am of the view that, given a choice, I do not see why anyone would select a living arrangement which involved so much movement from house to house."

GiveKidsAChoice : Bird Nest Custody (http://tinyurl.com/GiveKidsAChoice)

The biggest hurdle is finding an attorney who works for you and not to just drain your wallet.

If you want to learn how to do all this go to Dads House in Yahoo Groups. There's an educational manual in the file section that can teach you what you need to know. Take the time to learn what you can and should do.

DadsHouse : Building a Shelter for Fathers/Children (http://health.groups.yahoo.com/group/DadsHouse/)
"Can We Tape?" (http://www.rcfp.org/taping/)
Fathers & Families (http://www.fathersandfamilies.org/)
Parental Alienation and Parental Alienation Syndrome Home Page (http://www.parentalalienation.org/)