I've been in four projects with a close friend whom I've known since I was 13, but we've drawn a line under making music together because we just can't make it work in the long term. Early on it always feels great - the songs write themselves, the gigs are great, and then.... Something happens, and it goes downhill. It's a shame, as he's a great singer and the loveliest man, but our last effort was enough to convince me that it was never going to work.
Andy, I hope your re-kindled bromance works well, my friend!