“Me chupa un huevo” is a very informal expression used in Argentina and other Spanish speaking countries. You can only use it with friends, because in other situation is considered rude.
A literal translation of this expression would be “an egg sucks me”, but this doesn´t make sense in English. A good translation could be “I don´t care” although in Spanish it is not so polite in Spanish. In Spanish the expression “Me chupa un huevo” doesn´t have any sexual connotation, it just means: “I don´t care”.