Wiktionary
sea sponge
n. sponge (animal)
Usage examples of "sea sponge".
He watched with interest as I gathered up the sea sponge and picked out a soap I liked (it smelled spicy, like him), then scooted my way over to him, plopping myself down so I sat on his thighs, facing him.
And yet I was to fetch a bowl of warm water, a sea sponge, and with my teeth only to hold it, bathe his genitals.