On the way home, Jeff was pissed at Matthew's rude behavior and decided to punish him. He could use the Chronivac to knock Matthew down a peg or two by switching his brother's three inch cock with his. If Matthew's was smaller, that was no problem as he could just use the Chronivac again to reverse the changes and find another way to punish Matthew.
"Jacob, I'm going to work on something for a bit, so I'll catch up with you later." Jeff said as he ran off to his room.
"Oh. Okay..." Jacob said with a sigh.
Jeff quickly set up the options between him and Matthew and waited for a minute before the changes occurred. He took off his pants and underwear and walked in front his full length mirror. In a moment, Matthew's 4.5 uncut cock greeted Jeff. Jeff grinned and went to see his brother to get his old cock back. Jeff would be giving Jacob a larger cock, one not as big as his own but it should cheer him up.
When Jeff walked into Jacob's room, he found a hastily written note asking if he could borrow his cock for a little longer so that he could get laid with other guys. Jeff smirked, shook his head and said "Oh, fine." before thinking about what he would do next. He could swap his new cock for a larger one, continue to punish Matthew, swap his body parts with other guys or call it a day.