Mistress Ariadne has her prisoner over the bench. She slips on some gloves and goes in, not for an ordinary cavity search, she is going in to find, massage and ultimately tease the prostate.
As she finds it, there are groans and moans from her prisoner. This doesn’t stop her continuing and going in deeply to stimulate and massage it.
A lengthily stimulation and tease, but without even a full orgasm.