The flip side of that is that when busines partnerships break up, they are often like some of the worst divorces.
Partnerships are not inherently bad, but they do require a lot of preparation, planning, and proper documentation to do them right. Setting everything up right on the front end takes a lot of time and money.
From what you've described in this thread, it does sound like a mutual referral relationship may be best for you at this time. None of this is legal advice, and you should definately consult an experienced partnership/LLC lawyer before entering into any business partnership.
Good luck and congratulations on the success of your business so far.