Business Partners Spouse

[Joe Cunningham]

I recently purchased a duplex in a partnership with a friend. The duplex has one tenant in place on one side and the other side needs some renovating before renting out. My question/problem is this; he and I are the only names listed on the lease and deed as landlords/owners yet whenever we are there working on the vacant unit his wife makes friendly with the tenants, which is fine, but she starts agreeing to things that are either not in the lease (us cutting the grass instead of the tenants) or agreeing to upgrade things in the tenants unit that are still in good working order. Now, I'm not against extra help but is she legally allowed to do these things if her name is not on any of the documentation?