Motorboating without an engine

It was the third time he'd reached into my shirt and grabbed my breast with his cold, slobbery hand. I jumped a little, glared, and was met with a large toothless smile.
"It's official," I sighed. "Your son takes after you."
"Hey! I have never touched your breasts," he declared.
"Well, at the very least, to date you both share the same sense of humour."

It was barely a week ago that the child in question had spent a mere minute scrutinizing my face before eagerly proceeding to motorboat my cleavage, offering up a suave half-smile once he'd finished.

"Clearly I need to start wearing shirts that have better coverage," I sighed.