Joe Lauzon and Dan Lauzon both ended up as successful MMA fighters, with the two brothers making it in the UFC and being known as exciting action fighters. It's no secret that the two didn't always get along, and based on these recently released videos, it looks like they used to settle their disputes by throwing down.
In 2005, the Lauzon brothers had a backyard fight basically under MMA rules, without time limit, elbows, or knees to the face. Slams were said to not be allowed as well, but based on the clips, at least one of them treated it as optional.