A young man is walking through a carpark, loaf of bread in one hand, swinging it gently with every step. A red-headed girl a few years younger walks in step with him, listening intently as he speaks.

"By definition, a line exists in only one dimension. That is, it has no width, only length. If you were to take this line and fold it back onto itself 180 degrees at its midpoint, it doesn't become twice as wide, only half as long."

"Mmm?" My niece tilted her head to one side, and looked expectantly at me, waiting to see where this was going.

My gaze was broken from the four wheel drive I'd been watching back out in front of us, and I turned to look her in the eye.

"Assuming a heterosexual is completely straight, like that line, if you were to take them and make them completely homosexual, that is pointing directly back at their own gender, they are still straight, but only half as sexual."

Her eyebrows dropped low over her eyes, and her chin puckered. She didn't laugh, she didn't make a sound.

My eyes turned to a vehicle just starting up beside us, and we quickly walked past.

"This breaks the law of conservation of energy and mass and whatnot, because what happens to what was the other half of the line?"

My niece grinned, and her eyes opened wide.

"It's given off as heat surely?"

"Sexual frustration more likely. And yeah, I'm sure that generates heat." I retorted.

I was really getting the old noggin ticking now.

"Bi would be 90 degrees I guess, and that would then be able to have a hypotenuse plotted to determine area. Neither straights nor homos can have area."

We entered a quiet residential street. I paused contemplatively for a few moments, during which time neither of us spoke.

"Wait, that's fundamentally flawed."

My idoliser as one of the greatest minds in the country suddenly looked dismayed.

"How?"

Taking my keys from my belt as we approached my front door, I spun them round my finger a few times before answering.

"Think about it, sexuality is a vector not a scalar."

She looked puzzled.

"You know I was never any good at maths."

"Being a lesbian doesn't point your sexuality back at yourself, it points it back beyond you. If you wanted your sexuality to point back at yourself, that would be hermaphroditic."

"Hmm, yeah, ok."

I opened the door, and tossed the loaf of bread inside to Mum. My niece placed a hand on my arm.

"Well, what about hermaphrodites then? That's scalar and breaks Newton's Laws."

My eyes rolled back into my skull and I stared at the ceiling.