The spell has some unplanned side effects

Luna and Hermione positioned themselves near Romilda, who was talking to some other students. Luna whispered the spell. Suddenly a small spark shot from Luna's wand and hit Romilda's ass, before jumping to the other three girls. All four yelped and jumped up, rubbing their asses as if someone stung them.

"Oh my ...," one of them said. "What was that?"

"Did someone jinxed us?"

The four looked around and Hermione as also Luna tried to not catch their eyes.

"Probably one of the guys," Romilda said and looked around to spot some guy nearby.

"Romilda," one of the girls said. "You hair ...!"

Suddenly all four shrieked as they realized that their hair was changing. Soon they all had long, blonde hair and a rather vacant look on their faces. "Hi, hi," one said as a Syltherin student walked by. The four girls kept shifting and that attracted the attention of some more guys. The two Gryffindor witches could hear some popping sounds as the girls' shirt buttons jumped off, giving way to their expanding chests.

It took a few more minutes and all four were led out by a group of horny guys, who looked like they would have fun with the four bimbos through the night.

"Wow," Luna said and grinned. "Not what I thought but seems it worked better than expected."

Hermione just nodded, speechless of what was possible.