You can also expect a high probability that the entire "friendship" will break down and they will want to end the lease early.

Like I mentioned previously, your expertise in the home buying process and recommendations for all of the fun issues that have come up since buying our home, as well as your friendship have been awesome.

My opinion is different then what others wrote here. although it is important to visit the properties this visit is a unique opportunity to forge relationships with the people that do the work for you there. take them to dinners develop friendship figure out who do you trust and who do you want to work with in the years to come. real estate investment is all about your team. build a teamAnd when you visit a property never introduce yourself as the owner of the property. best to introduce yourself as working for the owner.

, and ruined what was once a great friendship.   

Way too often these kind of things destroy friendships and family bonds, so if you like and want to keep your brother, your going to have to be ready to make it more then worth his while because it WILL disrupt his life, it won't feel worth the brain damage and disruption for the peanut's $, and it won't be, that's why us in PM manage hundred and thousands of units to make it worth while.

Make it more about a friendship and getting drinks to talk RE, go to meet-ups, and try and get in-person on weekends if folks are going to properties of their own or to showings.

@Hans C Hormann the fastest way to ruin a friendship, end a relationship, destroy a family, is via Partnership in business, lol. 

Just create genuine friendships with people.

I was advised by her that no agreement was necessary because of the close friendship shared with her husband and this would have been what he wanted.MISTAKE!

One conversation leads to two, leads to a friendship, leads to analyzing deals and partnering up together, etc.