Legal Question in Wills and Trusts in Florida

This is a complicated question. Just living together will have no impact on her will. However if they were to get married he would be entitled to what is called an "elective share" regardless of what the will says. The elective share works out to roughly one third of the estate. If he is living in the home, then he is probably a tenant, and would have the right to stay on until he was evicted.

Her will will control her testate succession. Living in the condo does not give him any possessory rights. If he contributes to the condo maintenance or payments he could have a lien for those contributions. HIs personal property would remain his after death. Figuring out whose is whose could be difficult. Mom in law can have a disribution of personal property by separate document if provided in her will and she can list out all personal items and who is to get them. The other state's probate laws may affect the other property in that state.

You need to speak with her about her estate and a Pre Nuptial agreement.