"I...I've never..." he wanted to explain that he'd never had sex that didn't have some sort of anonymity to it. This was new, different, and so far, he didn't like it. He had wanted it so badly just a short time ago, but now he felt that sentiment quickly fading. He wanted Priestly to just be rough, and cruel and mean and to not care because he knew he'd never see him again, and Mars was positive that this would be the end of their relationship anyway. He never wanted to see Priestly again, certainly not after this.
"Stop...talking."
"Stop...talking."