When one guy fucks 2 people of the same family tree. Such as 2 sister's or 2 cousins or any combination people related to each other.
"Dude, I fucked Sara and her sister Courtney"
"I can't believe you are lumberjacking that family tree!"
"I can't believe you are lumberjacking that family tree!"
by Eskimo brothers June 03, 2017