Considering that her first 'flight training' had been at Gohan's house and how Gohan's younger brother had unknowingly shown off his skill in flying, Videl wanted to show the young brat that she could now fly too.  "The first thing we are going to do is head to your place," Videl ordered as she started to fly there rather than use her Capsules.  Gohan just nodded, not seeing anything bad happen if they were at his place.  Not that he expected Video to do anything outrageous, but still.
While Videl had learned to fly, she was not yet that fast, so it took them a while to reach the Son family compound.  Seeing their approach, Gohan's mom came out applauding Videl being able to fly, since even with her martial arts training, Chi-Chi had never been able to do so.  Yet after they landed, Chi-Chi also passed on a message to her eldest son.  "While you were gone, Bulma called. She wanted you to head over to do a job for her."
"Wait, Bulma as in Bulma Briefs, the world-famous inventor and CEO of Capsule Corp?  What type of job does she have you do?" Videl asked, not realizing Gohan's family was so well-connected, given their secluded lifestyle.
"She is an old friend of my dad and sort of like my Aunt.  She helped make my Saiyaman suit, so I started working for her to pay it back.  So sorry about this, but I have to go," Gohan apologized.
"Yeah, sure, whatever.  I will stick around for a bit.  I want to show your brother I can fly.  So I might still be here when you get back," Videl said, giving him a look that clearly said that this was true, so he could fulfill the ends of their bet.  With another wave and bow of apology, Gohan took off and flew away, going so fast it created a sonic boom as he broke the sound barrier.
After being told by Chi-Chi where Goten was, Videl headed out.  She considered making another bet with the young brat that she could fly using the same terms she had with Gohan to pay the brat back for inadvertently teasing her and showing off in that first training session.
As she had learned how to track Chi during the last training session, she used it to help her find Goten rather than just relying on his mother's directions.  When she felt she got close, Videl landed and walked the final stretch, finding Goten hanging out around a small lake with a massive waterfall.   She gulped a little, seeing the young brat apparently going for a swim, and since no one was around, he was in the nude.  Videl planned on making a hasty retreat and forgetting about showing the brat that she could fly when the youngest climbed out of the lake for another dive from the waterfall.
Videl could not help herself, she looked, and her mouth fell open in shock as she laid eyes on one of the biggest cocks she had ever seen.  Living with her dad in the massive mansion and dojo, Videl had seen other cocks before when some male disciples of her dad forgot that the dojo was connected to Mr. Satan's house, and she came over.  So it was not lack of exposure to cocks which made Goten's the biggest she had seen, but his actual size, since it reached to his knees.