Ever since the swap, Mariah, the older sister of the family, has been helping David, (formerly Brad) fit in at high school. They quickly became best friends, finding things in common with each other, doing everything together. She would attend his soccer games, play video games with him, and take him and Brad to the mall with her friends, telling them the twisted story about the swap. David saw her as one of the more mature members of the family, but Mariah saw David in a different light.
It was after a hard day that David decided to watch television late at night, and Mariah joined. Her long black hair cascaded down her big breasts, she was fitted with blue jeans, and a black t-shirt. She lifted her bare feet on the coffee table as David took a quick notice. David was starting to feel brand new feelings when he was around her. He placed a pillow over his growing crotch, when she started inching closer towards him, shoulder to shoulder.
"David, I don't know If I have already told you this but, I wanted to thank you."
"For what?" David looked visibly confused.
"For swapping with Brad, or, I mean old David. Sometimes I imagine what would of happened if I swapped with dad, or if I became mom, I wouldn't know how to handle it. But you and Brad adapted to your new bodies and roles almost immediately. I'm surprised. And I'm grateful for you sacrificing your whole youth just so the family could keep living normally." she said, pushing hair behind her ear.
"Thanks. But you should really thank Brad. I was kind of pulled into this whole thing by random." David shrugged. He continued watching television when a felt a warmth near his penis, it began to grow when he felt a grasp around it. He immediately jumped up. "Mariah, what's your prob-" he was muffled by scrunched up panties being shoved into his mouth.
"Listen, I've had a crush on David for a long time, even before the swap. I'm telling you this now because I thought you'd be more accepting towards me, with all the time we spent together. I just can't hold it in anymore, I steal your used underwear when your not home just to smell and masturbate over them." David tried to pull out the panties when she pressed a finger against his lips. "Ah ah, keep those in. You're about to experience something amazing. Just relax."
She took off her jeans, and threw off David's shorts and underwear, lowering her pussy near his cock. "Take this." she said, passing him a wrapper. "What is this?" David asked, unwrapping it.
"Its a condom, put it on so you don't get me pregnant." Mariah sighed, positioning his large cock with her delicate fingers. "Now, push it in slowly and be quiet." she demanded. His cock glands brushed against her pussy, before she sat down onto his cock. They both started moaning as quietly as they could. Her ass slammed against his thighs, his fat cock deepening inside her. David got more aggressive, holding her thighs and milking his cock, enjoying the pleasure of being sucked in by a real pussy. His hand cupped around her big breast, feeling the weight of it and circling the nipple, while she kept pushing on him. The moaning and flesh slapping together got louder as David felt his testicles begin to lift, filling up the condom inside Mariah. His cock slowly left her wet vagina, leaving the full condom inside her.
She pulled out the condom, eagerly drinking the semen. "That was great, I love you, David." Mariah said laying down, with barely any energy left. David picked her up, taking her to her bedroom. He locked the door and got in with her, spooning her sweaty body. David kissed her goodnight and slept.