Yes he is

Adam had a secret. For a while now, he had harbored a secret lust for his twin sister. He had yearned to feast his eyes on her breasts and pussy, but she was always so conservative, always so careful to be proper and not show any skin. As he held his naked sister now, he almost couldn't stand it. His cock was nearly bursting out of his pants.

Alice was distraught as she could feel her brother slowly grinding his crotch against her, but was distracted when she looked up and saw Rachel recording her and her brother on her phone!

"I hope you don't mind, Alice. I just had to record this adorable meeting between siblings!" Alice gasped and pressed her body closer to Adam, who involuntarily moaned. Alice looked up into her brother's eyes, confused. "Adam?"

"Holy shit, he has a huge boner!", Rachel yelled, focusing the camera in on a close-up shot of Adam's bulge grinding against his sister's pussy. "Wow, Adam! Are you really getting an erection from looking at your sister?"

Rachel walked slowly up to him and leaned in close. She began to rub his cock through his pants, whispering," I have to see this. You don't mind do you?" Adam was a whirlwind of lust and feelings as he stared from Rachel's gorgeous body and her hand rubbing his cock, to his naked sister and back again.

"Ummm...well...I...I" he stumbled through, before Rachel began to unbutton his pants. She slowly lowered his fly, and with one smooth movement pulled his pants down to the ground. She ran her fingertips over the massive bulge in his boxers. Suddenly she turned to Alice. "I'm pretty sure this is because of you, so why don't I help you out? With that, she grabbed Alice's hand and **** her to place it on her brother's rock-hard member.

"Noooo!", Alice cried. "Please, Rachel, it's wrong! He's my brother!" Rachel pressed Alice's hand harder against her brother's cock, forcing her to feel it's shape and rigidity, as Alice became acutely aware that there was only a very thin piece of fabric seperating her from actually touching her brother's penis.

Mrs. Sylvia was simply enjoying the show at this point, happy to let Rachel run things for a bit, all pretenses about why Alice was being **** to do these things abandoned.

"Ok.", Rachel said, "Time to make this happen." She hooked her fingers on either side of Adam's boxers before pulling them down and loosing his throbbing cock. Rachel grabbed Alice's hand again and slowly brought it closer to Adam's naked dick.

"Nooooooooo, God no please!" Alice begged. She fought as hard as she could, as Rachel brought her hand within inches of touching her brother's hard cock.