My fiancee has a will he states that I have life uses of his house can his children make me move if he passes away

It sounds like your fiance is trying to give you a life estate in his house. A correctly written Will can give you a life estate. A life estate means that you get the right to use the house as long as you live. You are responsible for the insurance, maintenance, repairs, property taxes, etc. as long as you are still living. At your death, the property would then automatically pass to the remainder beneficiaries named by your fiance. His children would not legally be able to make you move out of the property, unless you stopped taking care of and paying the expenses. If you allowed it to go into disrepair, stopped paying taxes on it, or otherwise caused the property to be damaged or potentially lost, they could sue to terminate your life estate for your creating "waste." However, it is very easy for a badly-drafted Will to incorrectly try to create a life estate, and fail. That can create major problems for both you and the intended remainder beneficiaries. It might even result in the children being able to make you move out. It would be better if he either (1) left you the property outright and gave other assets to his children (like life insurance), or (2) had his Will create a trust to hold the house and some liquid assets to pay the expenses. A trust is still difficult to draft correctly, but done right they can work better than a life estate. If he is willing to consult an experienced estate planning attorney for a review of his existing Will and make any changes that may be needed or desirable, then that's not a bad idea.