It wasn't the mascara, it was a small palette of eyeshadow, with a tiny brush with an ovoid head and a very thin handle, almost a miniature lollipop, and She put the head of it in Her mouth to moisten it. She squeezed out a dollop of the toothpaste, and leaned forward to whisper in my ear yet again. "Think about how this is feeling," she said. "Don't make a fucking sound," she finished, and started to paint my scrotum with the toothpaste, pausing each time she refilled the brush surface to admire her handiwork.
At first the sensation was just a coolness, a damp in the air type thing, but it slowly changed as the paste remained on my skin, turning warmer and warmer, then suddenly starting to burn, as the soft skin became more and more irritated. I twisted my pelvis from one side to another, trying to escape what was quickly becoming excruciating pain, when She grabbed my cock just below the head and murmured "Hold still for this part, and watch. If you move, it might hurt even more. But maybe you'd like that."
And she reached back to the carryall and took out some lube in a single pinch packet, ripping it open to massage a small amount onto my dickhead, dribbling the rest down below my now aching scrotum, until it dripped into my anus.
She poised the brush head up right on top of my cock. "Didn't really need much lube here, did you?"