gasoline pump???

A guy goes to a costume shop and says, "I'm going to a costume party as Adam and I need a fig leaf."

The girl brings out a fig leaf. He says, "Not big enough."

She brings out a bigger one. He says, "Still not big enough."

She brings out a huge fig leaf. He says, "Still not big enough."

She says, "Listen, Ace, why don't you just throw it over your shoulder and go as a gasoline pump?"