How you feel is just how you feel, it's neither "right" nor "wrong".  It seems to me that you have been very generous to him and his kids in giving them somewhere to live when he was in need - but not surprisingly you no longer want to do this.  Learning to be a new mother is extremely taxing on a woman in every way, and why should you look after another 2 kids as well?  I would tell your bf what you have said here, and don't sugar coat it - most of us here would agree that firm boundaries are a must, in step relationships.  

Well... you are not wrong for not wanting to have to deal with steplife.  However, it probably would have been a good idea to decide on that before you got pregnant with your BF (who seems to have a problem spreading his seed around.. and whatever else.. hope everyone has been tested).

But, at this point.. the horse has left the barn.. too late to close the door.  

So, that leaves you to decide what you want for your life.

Is the juice worth the squeeze here?  Is your boyfriend really all that great..  What caused him to lose his apartment?  Does he work?  Does he have substance abuse issues?  Do you think he is at all faithful to you? now? Why does he make it your responsibility to watch kids he created with another woman.. one created while you were somewhat together with him?  

Would you be better off on your own.. no BF.. with additional kids to deal with.  You would file for child support for your own child.. and likely share some custody with him.. but you would not be subject to his other kids any longer.. move on.. live your life?  

Hey, blessingstruly,

You’ve asked, … am i wrong for wanting to break up cause i don’t want them…. As far as I’m concerned, your partner, rather than his other young children, provides the best motivation for breaking up! The guy has already shown himself to be an unfaithful user. How nice for him and his alternate baby mama, dumping their littles ones on you, even while you were pregnant yourself. And, he moved in with you because he was unable to keep his apartment?! 

How many red flags do you need, to bail from this outrageous set-up? Thankfully, you’re not married, and will be better able to limit the boyfriend’s access to your infant; I suggest that you breastfeed as long as possible since doing so will also restrict visitation. Throw him out and file for child support! Continuing in this mess will only destroy your young life.

Welcome, I hope that you find this to be a good place to vent, contribute, and to pick up some useful perpsective from others who are living the adventure of the blended family dream.

It sounds that you are not interested in a life partnership with the baby daddy.  If that is the case and you want it to just be you and your new little one, then end it, move out of state, or at least outside of the long distance visitation radius,  and minimize the presence of the biodad and his children in your LO'ss life.

My DW was a single mom to a 15mo old when we met. She had left her home state for university.  Though my StepSon knew his Spermidiot and the SpermClan and ultimately his three younger also out of wedlock SpermIdiot spawned half sibs by two other baby mamas, his real life was with his mom and with me.  We married a week before my SS turned 2yo.  My DW never returned to SpermLand to live after leaving for university. That is likely the key success factor in how my SS-32's life turned out.  He is an only in our marriage.  He is an adult of character, honor, and standing in his life, profession, and community. His three younger SpermIdiot spawned half sibs include one on the dole, one convicted felon serving a long prison sentence, and one who is not far behind the inmate.  Who a child is around matters. Keep that in mind.

If you move a distance away, you will have zero need to ever see his first brood of failed family progeny ever again, and your own LO will likely only have limited exposure to them as is usually the case with a long distance visitation schedule.

If you choose to remain in your current home and location, re-key the locks and put daddy on the curb. He can figure out his own living arangements and how to pay child support to two different baby mamas for 3 young children. That... as they say. Is not your problem.  If you gird your loins and stand firm, there is no reason to ever see his elder children or their toxic BM ever again even if you remain local.

If you choose to stay with this man, you also choose to have his first brood in your life probably for the duration.  Their toxic bio mom will also be a part of your life.  Sadly, she and those kids will also be a major part of your baby's life as well.

Your call.  What every you choose, I suggest staying the course on your decision and minimizing the drama in your life and your baby's life.  

Take care of you. Take care of your little one.

The dude had no qualms messing around not just with one woman, but two (doesn't matter that one of you tolerated it), as well as with two whole little human beings whom he brought into this world, and who had no say in any of this! 
He then proceeded to leave the three of them behind so that he can mooch off you, while also using you as a bang maid/wife appliance? While also bringing the third child into the world? 
You and your child are just a blip in his string of failed relationships, you two are not the first and not the last. Cut him adrift already and watch peace and financial well-being returning into your life. 

There is no right or wrong in this situation. You are absolutely entitled to your feelings. What WOULD be wrong, however, would be if you forced yourself to stay in this situation because someone said you should. Do what you and your baby needs - that would be the right thing to do. 

I think you've done more than enough for the user. Start by telling him that if he isn't there then nor are his kids. The minute he walks out the door,  they go with him. He takes care of them, not you. He feeds them, not you. He deals with their mess, not you. He feeds them, not you. 

Or you can just kick him out now and seek child support. 

Be kind to yourself. 

That exter bed room is now bio baby's room. Start by cleaning it out. Put in a crib and other bio baby's stuff.  There is no place for SK until BF gets a job and rent. A big enough application for all to have rooms.

He can see his kids at a fast food restaurant.   And rent a Air B&B to keep them by himself.3