Harry Potter: having magic affects ones cock, bust or ass size

Many years ago a study my the Department of Mysteries within the Ministry of Magic learned Magicals took note of a change that seemed to have happened to Magicals the longer their family was connected to Magic. As if Lady Magic herself was charging them for using her gifts. It seemed that most Pureblood Magicals who were male would come to possess cocks that would only be able to reach at most five inches while erect. The use of Engorgement Charms would never affect them no matter how advance the spell was. Female Magicals on the other hand would be gifted with large breast and asses.

And while the Pureblood males seem to be getting smaller all Muggle and Muggleborns were found to be no smaller than a full foot in length while erect, with some managing to top even two feet. Engorgement Charms were found to be able to effect those who came from the Muggle world just fine, unlike their Magical counterparts. While after studies were done it showed that there had been no real change to the body of female Muggles/Muggleborns.

When it came to those considered Halfbloods it seemed the change when it came to males was a fifty-fity chance. While female Halfbloods always took after their Magical side and were gifted with massive racks and asses.

As Magicals took note of this many Magicals, apart from old Families such as the Blacks, Malfoys, began to start to hook up with Muggle/Muggleborns creating an influx of Halfblooded Magicals.

Who shall we follow in this story?