I have 3 step boys, they have stolen or destroyed several thousand dollars worth of things I owned for years before I met their mother. Had a truck totaled by a 15yo with no DL. Went to jail for 8 days, 150hrs community service and $2500 in fines...i spanked them for bein thieves at their mothers behest, daddy didn't like it. The middle child readily admits that his first answer to a question is a well thought out lie 95% of the time. He hasn't passed a class in two and a half school years and has to be told everyday to do the same chores. The youngest is 10, doesn't know how to flush or wipe yet, left me a 45 second voicemail full of sailors language when he's was 5. The oldest is in his third year of bein on his last year of high school, refuses to work, he is amazingly good at havin sex with a never-ending string of girls in his downstairs apartment, he is 18, so it must be ok. Not too sure why I'm still here, I love my wife like crazy mad. My children are 22 and 20, again...not too sure why I signed up for little thieves and liars for ten or more years...

Run away man...fast...

duties rest squarely on her shoulders.

They are engaging in "attention seeking behaviors." Even negative attention is attention. She is not and effective parent, and most likely suffers from "divorced mommy guilt" meaning she doesn't want to traumatize them any further, so she gives in and gives them their way. Your daughter will soon pick up on this, and it will rub off on her.

Another point to keep under your hat is, as they get older, they do not get better. It gets exponentially WORSE. Flip on over to "Adult Steps" for a glance into your future with these boys, if no intervention is taken.

Dr. Henry Cloud has a series of book on boundaries. They are very good. He has one on Marital Boundaries, and others relating to various areas we need healthy boundaries in.

Always remember, no matter what you think you love about this woman, it will quickly morph into resentment if she doesn't align her thinking with yours and discipline these kids. You have to be ON THE SAME PAGE.

It's also important to note, no cooking, sex, companionship or whatever else you deem an asset from this relationship is worth the hell you and your daughter will endure if these boys are not reigned in.

Sounds like while she is an amazing partner, she is a less than stellar mother... 

If she doesn't figure it out soon, I concur, run. Fast and far like your @ss is on fire. If they don't get better, they will get worse. And God help you if you decide to have children of your own with this woman. 

I would suggest two things - firstly that you own your authority over these two little boys - you and your partner are the bosses and they must obey.  Don't be afraid to be really strict and raise your voice if necessary (I'm sure it will be with these two)  - employ time outs or whatever discipline measures you see fit.  Be consistent and be VERY firm.  

Secondly, I would suggest you both read and watch some TV programmes such as SuperNanny which model firm childcare and parenting methods, and read some books on the subject - there are plenty on Amazon.  It is very important that you and your partner are on the same page where rules and boundaries for behaviour are concerned.  

The problem is your SO.  Find one who is capable of being your equity life partner and who will not allow children to destroy her or the relationship.

Take care of you. Take care of your daughter.  Put this shallow and polluted gene pool behind you.

First and foremost, you are the full time parent of a little girl. I would be very worried about the influence and impact your gf's sons could have on her, as well as her personal safety since you say they become aggressive and violent. That should be a deal breaker for you.

Please be very, very choosy about the people you allow around your daughter, and don't introduce women to her unless they're likely to be a permanent fixture in her life. 

As tog points out, your gf is an ineffectual parent, and it's a huge red flag that she claims she doesn't know what to do. You see, parents simply don't have that luxury, especially mothers. There's just so much parents are supposed to teach their kids, and only so much time in which to do it. She may be a ten and a tiger in bed, but being a shi!!y parent will soon eclipse any other good qualities this woman has. Cut bait, and move on.

In reading your post, you mentioned that she has no idea what to do either, to the point that she is self conscious about it. This doesn't make her a bad parent, she just needs a little help, if she refuses the help then you will know where you stand. 

Unpacking this a bit, she most likely is dealing with the Mommy guilt (as mentioned previously), pressure to make them feel wanted in a new relationship, and let's face it, kids do not come with instruction books.

The Mommy Guilt needs to be addressed by you. After everyone is in bed, sit at the table with her and work through this. Advocate for her because it sounds like you do want a future with her. Don't throw the ultimatum out that you're leaving if she doesn't fix it by this time. But you should say "I want this to be successful for both us and the kids, and the only way we can do that is if we map this out together so we both know the path forward". If that path is to taking a step back to give her the opportunity to focus on the kids, so be it. It may also be where you do it together, not my place to tell you how your house should run, but am telling to what's worked for me and my husband. Set milestones that you both can agree to like the"80/80 rule" she does 80% of the discipline 80% of the time. This gives her a little grace at first while y'all are working through things. Maybe go for doing a marital meeting before bed the first few weeks, not a formal one, but a loving one. Both of you laying in bed, face to face, no phone old school "Pillow Talk". Talk about the day, what was hard for both of you, what your partner thinks about the situation (honesty is key here), how things were handled, and suggestions (from both parties) for next time. Start with things like this, then come back for the sit down in a couple months to see if you can handle the level and pace of progress of there is any.

Next thing, the pressure of a new relationship. The she and the kids may still be in an adjustment period, the difference is that she is excited for your relationship the kids are still cautious. They know that you're not the Dad, and that things are gonna be different so they are going to spend quite a lot of time and energy discovering (usually repeatedly) where your pressure points are as a means of self preservation (feeling, worth, or whatever). This, this is the part that sucks (excruciating so), and it's also the part that seems to last for freaking ever. Don't disengage then freak out. Whatever you choose, just be consistent, your consistency will let them know that you can be trusted (if anything you can be trusted to react certain ways) which gives way to stability. Once things aren't new (this new period can go into a couple of years, especially as they hit puberty), things will level out one way or another. This works out the best when you're a United force. Example, as the step mom, i don't make a decision without my husband and I make that clear to my step son. His dad does the same for me, he doesn't make decision without us making it together. If a punishment is in store, we have him sit on his bed till we hash it out. Same thing with rewards too, we make those decisions together. Granted, this is what has worked for me and my marriage, i don't know the dynamics of your relationship.

Lastly, kids are hard, anyone who tries to tell you otherwise is lying. Yes the broad concepts are easy to follow, but sometimes the application or enforcement of those concepts are brutal, and you make mistakes. If you do mess up, sit down and tell them so together as a unified front. Even if the decision was really yours or your girlfriend's, you stand behind them and support that decision (even if it's burning down in flames), tell the boy you messed up and that we're gonna try something different or try harder to think it through (whatever scenario you got going on here). Being able to admit when your wrong will build that bridge of trust which makes things easier.

Granted, my husband and I do all of these things in tandem and it's worked well for us, so much so that I married him. His Ex is still batshit crazy, and our son is in therapy from the abuse he's gone through, but my husband is my other half. If it's truly the healthy relationship you think it is, you can make it work together. It sucks, no lie, it sucks, but you will be able to make it as long as you're openly communicating and supporting one another.

Hope this helps.

Wow .. If this is truly a woman you love dearly and if you care for her sons, then get the two of you to a good counselor.  I've seen that behavior including the boys acting out with their mom but different is doing something solo with me.  She needs to realize that she seriously risks losing you.  Bio moms need to stop being Concierge and Helicopter.  If she is committed to making a solid relationship with you then she needs to talk, listen, share and to meet you half way and you have a consistent, united front to the boys.  Otherwise, gracefully cut your losses and move on and someday when her darlings are 30 and living on her couch or possibly in jail, it could have been avoided had she worked with you.