Dr Satine has discovered a phenomenon she has called "natural viagra" - a condition where males are fully erect without any stimulation. She is presenting a seminar on it and demonstrates in front of her female colleagues by stripping a male subject naked. When he drops his pants the women are shocked at how erect he is! They prod at his cock and grasp how hard he is, but wonder if it works properly. The three of them then give him a blowjob until he cums on Eve's cleavage!
