Dave's Wines & Liquors of Oceanside, New York offered up a true gem in its 1985 party book. Grapefruit Soup Cerise calls for canned cherry pie filling, grapefruit juice, cherry-flavored liqueur, and grapefruit sections, along with sweet spices (cinnamon, cardamom and mace). This is supposed to be a starter course, despite the dessert-like ingredients. It sounds even worse than the junior high home ec "hedgehog salad" that involved covering half a pear with whipped cream cheese and sticking halved grapes and blanched almonds on it. (My recollection is that actually tasted just fine, but I can still make fun of it. I really can't imagine what the cherry pie filling and grapefruit soup would taste like.)
I'd just go for serving a half grapefruit per person. Except that nobody serves grapefruit anymore since everybody and his cousin is on statins, but that's another subject.