[This was a custom request] You head into a nearby clinic after hearing that they need semen samples for medical trials. When you arrive, the nurse is very professional but friendly, nonetheless. She explains that this clinic is different in the fact that they don't provide pornography for the clients. She informs you that the nurses retrieve the samples from you themselves, as they believe that it makes the semen more fertile and that she'll have to stimulate your penis to make you cum. She slips on some latex gloves, lubes up your cock and begins to jerk you off while asking questions about your fertility and medical history. She suggests that she use her mouth to stimulate your penis, as the nurses often do, and begins to suck your cock. This feels more intimate that the jerking, so you start to ask her questions about herself. She explains that your sample is particularly special to her as it's going to be used to impregnate her very own girlfriend who's in the waiting room next door. She's a lesbian and has never had intercourse with a man before so is therefore a virgin, she sees these oral acts as purely professional. But she's, unknowingly, really turning you on.... You feel yourself approaching your orgasm so she grabs a cup and finishes you off into it. She uses a syringe to collect the sample from the cup and thanks you for your time and the huge sample that you've managed to give. But your cock is still hard. Alone in the room with the nurse, you overpower her and spread her legs. You grab the cum filled syringe and push it into her pussy, emptying the entire load inside her. She's disgusted and worried that you might've already gotten her pregnant with your sample, but you need to be sure. You pull out your still hard cock and shove it inside her, fucking her virgin pussy while your cum from her very full pussy leaks out around you. She begs you to stop and reminds you that she's a virgin - and a lesbian! - but you pay no attention and continue to have your way. Eventually, although still very unhappy with that situation, she admits that you do feel quite good inside her. Still, she doesn't want you to cum in her again. With your fertility levels, she'll probably get pregnant with triplets after two big loads. However, still thinking about her girlfriend and the money that they'll make from the medical trials, she decides that if you promise to return with a sample for her girlfriend too, she'll let you finish inside her. You've barely agreed when you spill a second cumload into her twat, impregnating her with your seed and watching it dribble from her used little pussy. You'll definitely be back next week with another sample for her girl too... (to be continued)