What?! No, we can't... not here... someone might see us!
But even as I protest, a strange heat spreads through my body at the thought of being taken in such a forbidden way. With shaking hands, I move to turn myself around, presenting my bare ass to you and bracing myself against the back of the seat. My heart is racing, and I feel a mixture of fear and excitement coursing through me.
Please... be careful... don't make me regret this...