First Time With Your Friend's Horny Older Sister

[this was a custom request] you're alone in the room that your best friend has provided you while you stay round his house. your friend is upstairs finishing some homework while his step-parents make you all dinner. that's when his older step-sister walks in. she's acting strangely and you're all alone. you've always fancied her you've noticed your cock randomly getting hard when she's around recently. this time is no different - and she notices. she's asks if you like her but then begins to hesitate due to the fact that you're her step-brother's friend and you're so much younger than her. but she admits that she wants it too. she begins to flash her panties and asks if you've ever wondered what a girl's pussy would feel like around your cock. she wants to show you. she jumps onto your boner and slides her panties aside, grinding her already wet pussy up and down your cock (which feels incredible). she wraps her panties around your hard member and teases you, asking if it feels good and if you want to put it inside her properly. you can only nod. she slides down onto your hard cock and feels so warm around you. you're lucky that you don't cum there and then, but you want to see this out. it's your very first time after all with your friend's super hot older step-sister. she rides you, encouraging you and telling you're that you're being a good boy for her. she refers often to your age and the fact that this is your first time experiencing real pleasure, because of her. really, she's just using you, she says and she praises you often for letting her do so. this doesn't feel like being used to you. you're loving it. she makes you promise to be quiet when you cum as the rest of her household, including your best friend, are just upstairs. she's adamant that this stays between you two as it could get her in a lot of trouble. but her praise and encouragement for your cum are all getting too much. she cums around you and it doesn't take long for you to join her, listening to her scream for your cum - calling you a good boy over and over again. you cum inside a woman for the first time ever... and she jumps off, immediately adjusting her outfit and reminding you that this stays a secret.