OJ & Guinness?
Guinness and OJ in the same glass?? I had to double take your post for a minute. But after having done some research there is actually a name for this. its called WASP STING!! The following is from the guinness collectors club:
"Guinness mixed with orange juice (preferably freshly-squeezed and chilled). So called because the colours of Guinness and orange juice are the same as a wasp's. Incidentally, black and yellow are danger signals in nature, and after tasting this drink we can understand why...."