At the point when a male/female is eating a girl out and she has her menstral period in their mouth.
"Fuck man, i was eating Peggy out and she fucking beatle juiced!"
"Did you hear Mildrid beatle juiced in Donalds mouth."
"Beatle juice tastes sour, kind of like the puke tasteing jelly beans. Sometimes it's chunky and flakes of hard pieces get caught in my braces."