"if you must stay in the relationship get the water bottle treatment ready and when she acts out ya spray her full in the face with the water ..
your kid too.. and then you laugh at the look of pure shock ."

Laughing here - that's my preferred method of dealing with most of these brats. (see my signature)

Honey I am really really trying to come up with something helpful to tell you but honestly all I can think of is: You got yourself into this mess, then made it worse. Get yourself out.
I've been with my boyfriend for 4 years and guess how often his kids are at my house? Always..Why? Because we live together and because he has full custody of his kids. Guess how many kids we have together? Zero. Why? Because I don't want to be in your situation. It isn't an impossible task. I take responsibility and prevent myself from being in a situation where I would have to make difficult decisions. You really have two options here. Learn to live with it or get out. There are no soft options. You will be hard pressed to find sympathy here when you already knew you hated his kids, weren't already married to him, and ended up pregnant. Some women would die to have the father of their child around. I get that bad behavior is hard to deal with but one thing I've noticed is that everyone's Biokid is somehow 1000% better than their step. Everyone. Just like I'm sure your child is brilliant or advanced or something. We all like to look it that way. Point being, take a step back and look at this kid's behavior. Then imagine yourself cutting her some slack and not dealing with what doesn't pertain to you. Set some boundaries for yourself and stick hard to them. I'm sure we all think our way is best and we are parent of the year. Reality check time. Kid's are annoying. They don't always do what they are supposed to and mostly piss you off when they aren't yours. Sooner you accept that the easier it gets.

Sorry if I offend but that is the God's honest truth.

Hmm I don't feel any of you were supportive at all. Infact some of the stuff you, while true, was down right mean. She's venting and looking for support and advise. Not for you all to judge her. Where are the regular stalk bunch?? They all give great advise and support!

I have been in your shoes. I fully understand. It is really hard esp when you are not working AND have a baby on the way. Makes you feel incredibly stuck. I would not recommend making your bf get less time, that means he has to pay more money. Regardless of how often you have the kids, what you need is to sit your boyfriend down and have the talk. Set boundaries, expectations, rules, compromise, figure out what EACH one of you want and need from the other, what you will and will not do for his kids-ie: pick ups, drop offs, baby sit and how much, pay financially, if he pays CS then how much will he pay for your children meaning is he broke after paying BM and spoiling his kids so much that you and yours will always come last financially, what boundaries are needed between him and BM, disapline for his children, for your children and your newby together and what is acceptable from each adult to do to the others kid, ect. Do you see what I'm getting at?? Until you two can find some common ground in your relationship, home, with eachother... You will never see eye to eye on his kids. Meaning they will always be little devils and no matter how often you see them, they will always drive a wedge between you and him and the family you are making and the one he had before you. So, I recommend that instead of threatening to leave unless he stops having his kids so much is not what you need to make your family work, what you need is to have a heart to heart and find some common grounds and start putting them into action. Until then you guys are bound for nothing but disaster in stepHELL. best of luck!!! Keep me posted!! Also I would get a part time job. 20hrs a week. It will do you wonders in so many aspects!!! A mom always needs a back up plan to protect her kids.