This worked for me but I didn't do it with every client who wanted to spend time with me, it just clicked into place naturally with one and was only 'temporary' (I had a variety of things to resolve in my life). Now a fair few years into marriage! A year or two before this I did also became friends with another client, but this was on a clear "there'll be no other bookings basis" and no romantic involvement I knew it he knew it.