Grapefruit Margarita

"When I read about the evils of drinking, I gave up reading" - Henny Youngman It's Thursday! And Thursday means cocktails. Is this healthy? Probably not, but it does have a shed load of Vitamin C in there with the tequila so I think it just scrapes over the line. And grapefruit contains enzymes that help the liver break down toxins as well so that must mean that, um, er, something right? Oh who ...