Angelina is doing a thesis on male arousal for her PHD and she needs to study a live subject. She convinces flatmate John to drop hiw towel and let her watch his cock go from flaccid to erect. She gives amazing commentary and wide eyed cock shock as his dick twitches under her gaze. All on its own it becomes fully aroused and when she flashes her boob briefly John has to have a play. He jerks off in front of her as she encourages him and she cheers as he has a massive orgasm for her!