Reaction to vicariously experienced penile trauma... pleasure or pain?

There is something I discovered through prostate stimulation and the accompanying orgasms, but I have trouble articulating it so bear with me...

Do you know the muscular clenching and accompanying sensation you get when someone tells you about a physically stressful situation related to their genitals? For example, someone tells you they had a catheter inserted at the hospital, or describes a penile piercing, and you vicariously feel the sensation, which makes you clench in a certain way down there. This is often accompanied by vocalizations-- aaaah, ooooh-- and facial indicators of stress, not dissimilar to those vocalizations and facial expressions that indicate pleasure. I feel that those clenches and accompanying sensations of abdominal butterflies are very similar to the sensations that prostate play induces. To the point of personally being able to have an aless orgasm when imagining ultra-sadistic acts (that I may or may not ever partake in), or having these imaginary situations push me over the edge in an aneros session.

Am I alone in making this connection? And what does this imply? Does it imply a connection between successful prostate play and vulnerability? Or is it just that that instinctive reaction to hearing anecdotes (or remembering events from our lives) that involve penile trauma just happens to mimic certain sexual sensations? For example, perhaps our natural reaction to hearing those stories is to protect our testicles and penis so we clench abruptly and thus stimulate all sorts of glands and nerve endings simultaneously, thus mimicking certain sexual reactions.

I have my ideas, but I'd like to hear yours!!