Tempus Stamine

Tempus Stamine seemed like the best one, after all his cock was in fact growing, don't get him wrong, but it was doing so at a very VERY slow pace, so, all he had to do was just make his cock grow up to a certain size and halt the spell before he got wrinkly and saggy and grey. Aiming the wand at his cock, he chanted.

"Tempus stamine"

He expected his cock to start growing, to start producing hair quicker, but instead, it did the opposite, it completely began to shrink even further, what little hair he had completely falling off his cock and to the ground; panicking, Ron immediately halted the spell, staring at his smaller hairless pathetic dick he now had. Now, instead of the 2.8 inches he had, he now had the same cock he had when he was 11, when his dick was 1.9 inches long, completely hairless. He felt like crying as he realized that the spell meant ALL life stages, instead of all REMAINING life stages. And as if it couldn't get any worse, the doors opened.