As Lisa's pair of studded pussy tongues continued to caress and stroke Ty's pair of large cocks, she unzipped her mouth and said, "I can tell that you've enjoyed changing me, and watching the things I can do with those changes. And of course I've loved every minute of it. But although I've brought myself to orgasm multiple times testing out the changes, and with your feeding my pussies marbles and walnuts, I think we haven't focused enough on your own pleasure. Besides which, that just seemed like especially good foreplay, but we should do more that directly involves you in the fun."
Ty was so stimulated by the tongues that he replied, "Oh, you're doing a great job of pleasuring me! Don't stop!"
"Of course I won't stop, but I think I'll turn up the heat a bit!" Her tongue work changed a bit. Her left tongue started caressing both of his dicks, intertwining between them, and her right tongue briefly inserted its tip into the urethra of one penis, then the other.
"That feels incredible! I'm getting close, and I'm not sure I can hold it much longer!"
"Oh, I think you can if you try," she said. "Close your eyes," Lisa started sucking his nipples. The sensation was amazing, and he'd almost forgotten how much he'd enjoyed playing with his new partly-female body (which is mostly Lisa's body!) before she arrived. He remembered with embarrassment that he'd been very upset about the knock at the door!
He continued to feel one tongue stroking both of his cocks, and wondered what Lisa was doing with the other now. It still felt so good that he wasn't about to complain about not getting her full attention. Maybe she was using the other tongue on herself, which would only be fair. Then he felt Lisa's torso rise up above him, though the lower tongue action continued unchanged. This seemed curious, but he decided he'd find out her plan soon enough. "Good thing you made these tongues so much longer!", she said.
With that, she lowered herself, impaling her twin pussies on his twin cocks, though with a considerable length of her tongues still protruding. With part of the tongues on the inside, her pussies seemed even tighter than before, and both Lisa and Ty gasped a bit. Her pussy muscles were so strong that he was a little worried that if she had an orgasm, she might hurt him! She sensed him tensing up, and guessing the reason, reassured him, "Don't worry! I have enough control that I won't crush you like the walnuts!" She started squeezing his tits and sucking his nipples again.
His cocks felt the portions of the pussy tongues still inside her vaginas, wiggling around along with her muscles gripping and relaxing, rippling and twisting, and he was thrusting even as she was. Then he felt what she was doing with the rest of length of her tongues. They started licking his balls! They traced along, wrapped, and unwrapped around both of his scrotums, gently squeezing them, and sometimes not quite as gently. ("Scroti?" he very briefly wondered, but was far too gone into ecstacy to maintain a coherent thought.)
Just when it seemed that nothing could possibly increase the intensity of his arousal, he felt her lower tongues leave his balls, to be replaced by her other pair of hands. (The first pair, and her mouth, still engaged with his breasts!) And then he got the biggest shock yet! He felt one studded tongue start teasing his clit, while the other inserted itself into his vagina and started thrusting. With the unbelievable level of stimulation, he could no longer contain himself, and had the most mind-blowing orgasm ever, ejaculating incredible amounts from both cocks, but also, simultaneously, having a female orgasm. And then, to his surprise, under Lisa's continued ministrations to his new "lady bits", he had a second, then a third! "Wow, normal guys are missing out SO much!" he thought to himself.
Shortly thereafter he heard Lisa cry out, and felt her orgasms squeeze him over and over, but true to her word, she somehow kept enough control to avoid hurting him. At least, not hurting him much, or permanently.
Carefully he rolled over, and she shifted, so that they were lying side by side. They kissed, and Lisa's pussy tongues continued, now rather languorously, to stroke his cocks, balls, and clit.