Watching their show, and feeling himself get so hard, it was almost painful, Jon tossed the body stocking at them, saying, "Now put this on, Sarah." As they went about getting that on her, Jon quietly wished, "I wish that I could, whenever I wanted, change myself to have two fully-functional dicks, each the size of my current one, and change myself back at will."
He blinked as he finished saying it, and tried to will himself to have a second one. As his pants felt immediately more crowded, he was sure it worked. I sure wouldn't want to walk around like this, he thought, but it'll make a nice surprise for them.