The new woman in his life

Talk to your lawyer , tell him your concerns. Maybe you can get a court appointed lawyer to represent the kids if need be.
You know , I read things like this and am in a situation where my bf's ex won't allow the kids around me. They were allowed BEFORE we dated. If he brings them around me then she won't allow visitation.
It just ticks me off that the courts will allow your children to be around someone who is like they are and even involving alcohol and I can't be around his kids. I don't drink, I smoke but but in front of even my own kids, I have never had any type of charges filed , not even a traffic violation. I run my own company, raise my kids by myself because I was widowed( I have 4)  and I am not on welfare or anything like that. My kids are well rounded and even do well in school.  I just can't understand the legal system. Go figure. Lets keep away the good people and allow the abusers, druggies and alcoholics to raise our kids.
Go figure.

I wish he would sit down and have a conversation with me, since leaving in September of last year the only way he will communicate with me is by text message or phone conversation (which is usually strained and most times ends with him bringing up his justification for cheating and alcoholism)  I am concerned about my children's safety and the influences they are exposed to but he has repeatedly told me if I try to alter our parenting plan that he will "make sure I loose everything"  I have suggested that we meet with his counselor to discuss what would be in the kid's best interest but he refuses.  While visiting their father rules such as homework completion, and bedtimes are disregarded.  The kids enjoy being with him because anything goes and it is all fun and games at Dad's place.  I don't know what to do.

I would try and sit down with your ex and let him know your concerns.  Hopefully he is a good father and would not leave your kids with someone who would hurt them.

This is a tough call. I am not an attorney but do not think you you have any legal rights to "evaluate" the new girlfriend.  He is allowed to date whoever he wants but you are right to be concerned about the living situation if there is any abuse going on. The kids seem old enough to know what is right and wrong so just make sure you keep the lines of communications open with the children. Maybe try and talk to your ex and let him know your concerns about the drinking and being left alone with a stranger.  Do not let him know the kids have told you certain things.  You do not want him mad at them.  This is a tough situation.  Maybe she is a very nice person and will not harm our kids.  My only concern is that if it is his time with the kids why are they spending time alone with the new girlfriend.  Can you have a calm, civil conversation with your ex about your concerns or will he get defensive?  Keep me posted.