Yes, you do, and many others besides

You smile, having heard that riddle before. "The letter 'M,' of course," you say.

The centaur grunts in acknowledgement, before nodding for you to take your turn.

Cracking your neck, you decide that you're done with the simple warm-up riddles. "Only one color, but not one size, stuck at the bottom, yet easily flies. Present in sun, but not in rain, doing no harm, and feeling no pain. What am I?"

That one draws a pause from the centaur. She chews her lips in thought for a few moments, causing you to notice just how plump and full her lips are.

Then her eyes light up, and she grins. With a chuckle, she says, "A shadow. Hah! You'll have to do better than that human, or your ass is mine!"

At her crude reminder of what, precisely, is on the line if you lose, you shudder. Still, if she thinks that her mind games are enough to disrupt your focus, then she's in for a surprise.

Crossing her arms beneath her breasts, the centaur says her next riddle: "What is it that given one..."

Rocking back on your heels, you think about the centaur's latest riddle. The two of you have been volleying riddles back and forth now for nearly half an hour, now.

After a moments thought more, you confidently answer, "A tree."

As you solve her latest riddle, the centaur groans in frustration. Despite that, you can't help but notice that she doesn't seem to actually be upset. In fact, judging by the smug smile on her face, she seems to be enjoying the game more and more as it continues. She hasn't stopped making crude remarks, unfortunately.

Shooting you a lecherous grin, she says, "Damn, cutie, I thought that one would get you. One way or another, you've earned yourself a hell of a ride for this!"

"My turn," you say, before taking a deep breath. "I can't be seen, can't be felt, can't be heard, and can't be smelt. I lie behind stars and under hills, and empty holes I fill. I come first and follow after, end life, and kill laughter. What am I?"

The centaur herm shimmies back and forth on her hooves, her brow furrowed in thought. As her silence stretches on, you perk up. Are you about to win?

Finally, after several minutes of pacing and thinking, she stops and faces you.

She looks you dead in the eye, and says...