I am going to say you both need to sit down and talk, you both had kid's before getting together, my daughters dad got a girlfriend who had a son when my daughter was 3 his girlfriend had made everything about her and her kid, he stop doing the things need for his kid and now is not in her life, you both need to understand that that one-on-one time with kids is needed as well as doing family time, my ex has been threatened to be kicked out of his own house if he wouldn't do things for his stepchild and always choosing the stepmom and the stepchild over your own biological child will impact your relationship with your child just because you can't babysit should not be a reason to be threatening to kick you out of the house