Deborah,
Try going through this with a partner that you've bought out & they try to steal your phone #, old location & try to take control of your websites.

I can relate going through a situation with a partner that was similar to your brother-in-law, because of their unethical ways of doing business we bought the partner out, paid allot of money and they try to compete in unethical ways as well.
sure makes for tough "family functions"

My advice - ignore him & focus on what you are good at.

Think of him as a soda can, he's all full of bubbles and fizz for the short term give it some time and the gas will run out. any reputable customers of yours will not listen to none sense, anyone that does probably has similar views on business as your brother-in-law and is that type of customer really worth having?

Strong ethics & good credit are keys to success