@Warpbeast A friend of mine has a different surname than her sister since they are from different marriages so it's possible. Funny story, when she tried to pick her sister up from kindergarten for the first time, because of the different name the teacher didn't believe her and thought she was...
@pajamawolfie Guy here and I never heard of that one either. Wild guess maybe it's something of a regional thing. "Ay Seamus yee old twat, stop yer armswinging and get back to work !"