Patrick swam along with the mermaids, feeling free as can be now, swimming the ocean as he liked, his newfound older sisters keeping him safe from any dangerous places. However over time the enchantment they used on him seemed to be having some side effects. It was Lorelei who noticed them first. She was just finishing exploring an abandoned ship when she saw Patrick come swimming over...and almost bump his head. Because Patrick was now looking less like the six year old they took in and more like a ten year old.
Patrick for his part did not seem very distressed by what was happening in no small part because he did not understand what was happening to him. "I-I think I got bigger, Lorelei! Huh...yeah, I think I did..." He looked at his tail and its slowly improved strength and the shine in its scales.
Lorelei told Patrick to go play by himself for a moment while she had a chat with her sisters.
Nina seemed perplexed by the situation, "We did it perfectly, the melody should've just transformed him into a merman and let him grow up normally...no, you don't think it could be---"
Kelly stopped her and said, "If we talk about her, she comes back. Those are the rules. So let's just not talk about that sociopath, okay?"
They all nodded knowingly, not knowing Patrick was still within earshot, wondering what they were talking about, having stopped in his play by himself and wandered a little too close. But before long he started to feel funny, so he went off by himself again. As he dived and moved among the coral and sea life, he felt his body shifting and...changing, awkwardly. He bit his lip as it happened, his upper body growing taller, stronger, proceeding into his teenage years. His face started to change from prepubescent toward teenage. The girls would've called this boy cute for a different reason.
His body toned and developed a stronger contour, shaped by his time at the ocean. He started to feel a bevvy of confusing and unusual sensations and feelings from his newly 14 year old body. His hair was now longer, wavy and dark in color. He raised an arm and was shocked by both how long it was and how his upper arm looked. He was appearing to be more of a swimmer in build at least in his upper body.
His tail was thicker, stronger, more capable of moving through the deeper waters. He smiled wide, "I-I'm even bigger!"