"Uh, uh, uh-uh-uh," Mom panted, her yelps coming so close together they were almost one word. "Holy fuck, Mark--god!"
I slowed down.
Mom sighed.
I sped up.
Mom gasped.
I straightened my forefinger and eased it against Mom's lubed-up asshole alongside my middle digit.
"Oh, no, baby, no," Mom groaned, but she never used the word ...