Better to have it and not need it than the opposite.

Despite all the drama caused by his sister, things had ended going rather well for K-T, that is if he ignored the painful experiments and international humiliation. So decided to trust his luck. If Lily had planned to go further with him and stopped doing it because he didn't have his dick with him he'd never forgive himself.

The zip lock bag would be a bit noticeable though, so he removed his still hard cock from it and did his best to put it in his shorts pocket. K-T noticed that even after a real orgasm and a ruined one it showed no hints of going soft any time soon. It was probably a side effect of the device (even if he often had issues getting soft when at full mast, often having to jerk off multiple times to get back to a more manageable size), but it didn't help what he was doing. Thankfully the pockets of these shorts were just large enough to fit it with a bit of fiddling.

Finally ready, he rushed to the door and crossed the street to Lily's house, ringing the bell to announce himself.

After a few seconds, Lily came to open the door and to welcome him in. She had changed into a rather skimpy white bikini, her hair and body was still a bit wet and the material of the swimsuit was getting almost translucent on part of her breasts. The sight of her wearing this would have actually made him rock hard, that is if he had been able to get soft today at any point.

"Hey K-T, I see your sister passed the message. I think you're a bit too harsh with her. She's a bit weird with her science stuff, but she seemed very reasonable when I talked to her. And very enthusiastic about you working out, she immediately agreed to free some time for it. But I guess you're here for your reward. I see you showered already, it's a good thing." She told him, seeing his still wet hair.

"I like spending time with you, doing anything actually is already awesome. But yeah, I'm really curious about it. You said it would be a surprise." he explained.

Unbeknownst to him, rushing there had been a bad idea, his running had slightly dislodged his dick from his pocket and his balls were now hanging out of it.

He followed her inside to discover his reward.