Once Gisela took Kevin to Lilia's, scolding the girl for giving him the impression of being dumped while delivering her the potions she needed, Kevin's relationship with Lilia got back on track like nothing happened.
Not really nothing, since they now both lived in her little house and Kevin regularly saw Lilia's true form. It was clear she felt guilty for not revealing the truth herself, but her boyfriend understood her fear of his reaction and had immediately forgiven her.
Kevin also explained the relationship he had discovered between his twin-brother turned twin-sister and Gisela, and how they wanted him to help them have a baby of their own. Lilia had insisted he should help them, once she had sopped laughing at how he thought they wanted him to help.
Several month after meeting Gisela in that bar, Kevin hadn't heard of her anymore, and neither did Lilia, so when they heard someone ringing the doorbell, they didn't think it could be her.
Kevin had finally got past the phase were he was simply mesmerized by Lilia's tail, which while it looked to be a pale silver at first glance could, when the light hit it with the right angle, refract it into a myriad of tiny rainbow. So Lilia's was hoping to finally get some action in her natural form, and the only beings Kevin and her could imagine to be cruel enough to so rudely kill their mood were:
1- A door to door salesman
2- Satan himself (or his merfolk equivalent)
Still, Kevin hurriedly dressed up, urging Lilia's to stay as she was, promising to ‘send the demon back to were it come’.
Of course, once he opened the door and saw Gisela on the other side, he knew he couldn't execute his plan. “Gi– Gisela?!? Please enter, enter!”
Gisela was transporting a box full of potions, but that wasn't all. Among the potions Kevin could see a necklace similar to the one he knew she needed to have legs. Seeing he noticed it, she said “It's for you. It will change you into a merman as long as you wear it, down to the ability to breath under water.”
“Wha–? But I thought… !” stammered Kevin.
“And you were wright. But our scientist discovered that what prevented Maria from being able to breath above water was that she got too much of whatever make her a mermaid into herself. She had enough of that spiritual stuff for another person. Normally said stuff shouldn't be compatible with anyone else, but since she has an identical twin…”
A news that prompted Kevin to go fetch Lilia, barely giving her the time to grab a shirt, so the news could be shared with her.
Gisela, for her part, shook her head. “I didn't even get to say that he got invited to our submarine country by Lilia's family.”