I prefer to be on my knees or stomach, but you might like a different angle. Like you're trying to open a muscle and stretch it out and it doesn't want to listen. Sheet stains are a risk and should be considered collateral damage. The act itself and the thought of the act both turn me on.
At first, extremely unpleasant. If it is, a quick jump in the shower is all that is needed. I suppose any dude who's into anal wouldn't be so particular as to request a smooth entryway.