"If I must, miss, I would like to be able to be human outside of the water, even if I'm still a girl." You try your best to be grateful. "I'll find a way to make it up to you, I swear."
Circe smirks, walking towards you. "You seem glad that you can be human again. Are you certain, though, that you don't mind being female? I'll be honest with you - even if I do anything else with you, you'll always be a girl. This is your last chance to be male. Are you sure about this?"
Even if you did choose to be a guy again, there wouldn't be much you could do as a lonely merman in a closed pool. Gazing into the woman's eyes, you nod confidently. You're sure.
"Well, then, your request is granted." The woman points at you, and you feel a tingle in your tail momentarily. The feeling is fleeting, though, and you seem no different.
"I said that you can't be human when in water or outside the house. Come here and get yourself out. I'll lift you out myself if you can't manage."
No need for that. You swim the short distance to the pool's edge. Remembering tricks from countless summers at the YMCA, you turn to face away from the edge, grab it from behind, and push yourself up and out.
As you sit on the edge, you lift your tail from the water and lay on the floor. Suddenly, the scales start to recede and your lower half is enveloped in bluish light for a second. When the light ceases, you have a pair of perfectly healthy human legs.
Female human legs. And a choice few other healthy parts of female human anatomy. You're also nude, save for your rediculous seashell bra. Covering yourself with one hand, you look at Cierce. She seems amused at your nudity.
Slowly, still holding a hand in front of your crotch, you rise to your feet. The woman grins.
"You'd said you would try to repay me? You might be in luck. Let me think of what I might need..."