Vampires In Bar

Three vampires walk into a bar and the waitress asks, “What’ll it be boys?”
“I’ll have a glass of O Positive,” says the first vampire.
“AB Negative for me,” says the second.
“I’m the designated driver,” says the third, “So I’ll just have a glass of plasma.”
The waitress turns to the bartender and yells, “Gimme two bloods and one blood lite!”