Archly, she purred, “Ooooh? Prove it. Prove how manly and fierce you are.” She shifted back just enough to wrap her hand around his cock. Lightly, so lightly it might just feel like currents of water shifting around, she slid her hand up.
“Y-you’re holding the very t-thing I’d use to p-prove that!” He spluttered out and shifted slightly, his movements causing water to splash at the edges of the tub, threatening to spill over. Cursing quite colourfully then at the not-enough-friction, he whined and arched up, desperate to make her move that much faster.
Both eyebrows climbed high on her forehead at his words. The swearwords made her smile mischievously, and then she let go. “I’m not holding it now! So prove it.”