Really, you have to put the friendship first.

@Bill Piker, it is a business not a friendship.  

I hope that this proves to be a long and fruitful friendship/partnership for you two guys and everyone who worked with you on this deal. 

I wanted to go for it, but worry about loosing friendship/money/relationship/trust if something goes south.I understand we need LLC or some entity as well as partnership agreement is good start.

I have made great partnerships and friendships here.

I joined bigger pockets to network, learn, create friendships and form win/win relationships.If you live in my area, let's meet up for coffee sometime!

Not to mention the friendships and business relationships i formed thanks to BP. 

They are not your friends/good terms, they are using the friendship to prolong it....it never works out.First sign was when they were pushy trying to tell you what to do with the other tenant...your the boss.

Still do, it’s turned into more of a friendship than a business relationship at this point though.  

It doesn't have to be notarized or signed (just a simple email will do) but I have seen family and friendships ruined over not clearly understanding what they were getting into.If you can't get family to put up some money then go to some networking events and rub elbows with the investors that are doing deals.