Legal Question in Wills and Trusts in Massachusetts

The potential problem is that the girlfriend and her family will claim she has a life estate in the property. Her children would probably want her to get something in writing.

Whatever is done should be documented so that when your father-in-law dies, everyone knows what the deal is and there can be no dispute.

A co-habitation agreement should be drafted so there is no claim that she was promised half the house or anything like that. Likewise, if the girlfriend predeceases the father-in-law, you need to make sure that the girlfriends children are not going to have an issue.

What happens if one of them has to go to a nursing home in the future due to frailty or dementia?

If she moves in with him, then there needs to be a co-habitation agreement and you need to make sure both parties are competent to sign such an agreement.

There are a fair number of 80 year olds who know exactly what they are doing such as Warren Buffett, but there are as many if not more that while lucid are not as swift as they used to be.