Short term variance for a temporary roomate

[Scott Donnelly]

Hello all - I own a condo in NH that is rented to a responsible, quality tenant. I've been asked by the tenant to allow a short term roommate (new to the area) to occupy the 2nd bedroom for a single month before moving into a new residence.  I am inclined to allow it, although it is an explicit variance from the current lease.  What do I need to do to cover myself, and is there any advice out there for how to handle this in an ideal manner? Any form/document someone has used in the past to spell things out? Thanks all in advance.