This is a horrible situation, I was very recently in a similar one. Sometimes you have no choice and just have to think about what is best for your little child. If your partner staying at your house is getting in the way of raising your chid in a healthy, stress free environment then it might be best to force him to leave. (please see a lawyer for options)This is after exhausting all other options of course. The next year or so is very important to your child.