Girl, you must be a teaspoonful because you are the amount that a teaspoon can hold.

Girl, you must be a Frenchman because you are a man who is a native or inhabitant of France.

http://www.shutterbug.com/images/imagecache/960-wide/photopost/data/500/4391brooke_french_man_revised.jpg

Girl, you must be a sandbox because you are a low box filled with sand for children to play in.

Boy, you must be a blocker because you are agent noun of block; something that blocks something specific.

Girl, you must be a tractor because you are something that pulls or draws.

Boy, you must be a diarrhea because you are excessive and frequent evacuation of watery feces, usually indicating gastrointestinal distress or disorder.

Girl, you must be a stepson because you are a spouse's son by a previous union.

Boy, you must be a pile because you are a voltaic pile.

Girl, you must be a behaviour because you are chiefly British Variant of behavior.

oh god

Boy, you must be a domino because you are a country expected to react politically to events as predicted by the domino theory: "The dominos did indeed fall in Indochina” ( Arthur M. Schlesinger, Jr.)

:D

Boy, you must be a tubing because you are a system of tubes.

Boy, you must be a kiosk because you are a small structure, often open on one or more sides, used as a newsstand or booth

so much lols

Boy, you must be a solution because you are the state of being dissolved.

Girl, you must be a nephew because you are the illegitimate son of an ecclesiastic who has taken a vow of celibacy.

Girl, you must be a sulphate because you are alternative spelling of sulfate.

Girl, you must be a mantelpiece because you are chiefly Eastern & Southern U.S. See mantel.

ok this works:

Girl, you must be a beauty because you are the quality that gives pleasure to the mind or senses and is associated with such properties as harmony of form or color, excellence of artistry, truthfulness, and originality.

I get about four words into every single one of these and the laughing fit won't stop.

Boy, you must be an orgasm because you are to experience an orgasm.

Boy, you must be a Kaiser because you are any of the emperors of the Holy Roman Empire (962-1806), of Austria (1806-1918), or of Germany (1871-1918).

Girl, you must be a contrivance because you are something contrived, as a mechanical device or a clever plan.

Girl, you must be a rapper because you are one that raps or strikes, especially a door knocker.

Girl, you must be a Clift because you are clift, Montgomery 1920-1966. American actor known for his performances in Red River (1948), From Here to Eternity (1953), and Judgment at Nuremberg (1961).

^^^ nailed it

This one is coming on a bit strong:

Boy, you must be a housing because you are a hole, groove, or slot in a piece of wood into which another piece is inserted.

Boy, you must be a volleyball because you are the inflated, spherical ball used in this game.

Girl, you must be a Cordoba because you are alternative form of Córdoba.

Boy, you must be a fanfare because you are a spectacular public display.

Daaaaaaamn

Boy, you must be a heartache because you are emotional anguish; sorrow. See Synonyms at regret.

Girl, you must be a breeder because you are an animal kept to produce offspring.

:O

Girl, you must be a stalker because you are any of various devices for removing the stalk from plants during harvesting.

xpost maybe it'd work in utah

Girl, you must be a Chico because you are a city of northern California northwest of Sacramento. It is a processing and packing center in an almond-growing region. Population: 73,300.

Boy, you must be a drawer because you are underpants.

Girl, you must be a groundwork because you are a foundation; a basis. See Synonyms at base1.

Boy, you must be a stallion because you are an adult male horse that has not been castrated, especially one kept for breeding.

[lacks nuance]

Boy, you must be a locust because you are the wood of one of these trees.

Girl, you must be a skylight because you are light from the sky.

http://www.jiveturkeyjives.com/wp-content/uploads/2010/10/smoove-b.jpg

Girl, you must be a chimpanzee because you are a gregarious anthropoid ape (Pan troglodytes) of tropical Africa, having long dark hair and somewhat arboreal habits and exhibiting humanlike behavior and a high degree of intelligence

Boy, you must be a ramp because you are a mobile staircase by which passengers board and leave an aircraft.

Girl, you must be a pharmacy because you are a place where drugs are sold; a drugstore. Also called apothecary.

Girl, you must be a grump because you are to mutter complaints.

Boy, you must be a folk because you are the common people of a society or region considered as the representatives of a traditional way of life and especially as the originators or carriers of the customs, beliefs, and arts that make up a distinctive culture: a leader who came from the folk.

Girl, you must be a hostage because you are one that is manipulated by the demands of another: "National policies cannot be made hostage to another country” ( Alan D. Romberg).

(I keep thinking "I shall post this last one then get on, oh I might click one last time.." and so on)

Boy, you must be a reader because you are one who publicly recites literary works.

Like Morrissey, ..

Girl, you must be a purity because you are a quantitative assessment of homogeneity or uniformity.

Girl, you must be a nanny because you are a children's nurse.

Boy, you must be a pullback because you are the act or process of pulling back, especially an orderly troop withdrawal.

Girl, you must be a Starr because you are starr, Ringo Originally Richard Starkey. Born 1940. British musician who was the colorful drummer of the Beatles (1962-1970).

Boy, you must be a corpse because you are a dead body, especially the dead body of a human.