Now Ken knew that these two had not learned their lesson and giving them a penis the size of a horse's was not a cure, if anything it would just encourage their bad behavior.
It was just then Ken had a very adult idea. He changed the two to two very voluptuous 18 year old girls. He gave them the sex drive of the boys they would have been at 18, so very high. He gave them the immaturity of a toddler that wants what it wants when it wants it.
He decided that there might be an out for them but that out wouldn't be an easy out. If they had 30 children, no matter how old they were at that 30th, they would revert to the age they were at this point in time but with the memories of being a girl, the objectification of their bodies, the pain and the discomfort of their period and child birth.
Ken wasn't evil he just saw clearly that these two boys needed to learn what they were doing to girls and the only way for them to learn it was for them to be those leered at girls.