(This was originally filmed as a custom video) You've signed up for a mysterious trial asking for male participants to help develop new sex toys, and are pleased to find that the scientist taking you through the experiment is not only attractive, but is decked out in sexy lingerie underneath her labcoat! She gets you to fill out a quick form, apologising for not being able to give too many details about the product being developed, as it's currently a state secret, but confirms that it is indeed sexual in nature. She asks you to disrobe completely before placing electrodes on your body to record your nerve responses to stimuli, then restrains you at the wrists so that you won't accidentally dislodge the electrodes during the experiment. She then kneels down and begins examining your penis closely, recording some readings on her tablet, then begins to slowly tease your cock with her fingers and tongue. She seems pleased with the data you're providing so far and begins ramping up the intensity, gradually sucking you harder and faster until she's deepthroating and gagging on your dick. She reminds you several times to try and resist the urge to cum, as the longer you last the more data she will be able to collect! Next she moves your restaints so you can lay back on the examination bench, and she climbs on top of you to ride your cock, using various techniques to test your responsiveness and often checking in to make sure you're not getting too close. She's very pleased by how long you're able to last, telling you that you're providing a lot of extremely useful data for her study, and so she switches positons a few times to keep testing your limits. She's so pleased with your performance that she confesses to you the true nature of the sex toy being developed - how they plan to get millions of men all over the world addicted to it, and how you're the perfect candidate to demonstrate the prototype to their investors! She rides you furiously, demanding your cum and telling you that this last sample is all she needs! TAGS: british, english, redhead, ginger, posh accent, tattoos, medical, roleplay, solo female, dirty talk, med exam, doctor, scientist, dildo sucking, blowjob, cock sucking, dildo fucking, cowgirl, reverse cowgirl, stockings, tattoos