Lilia had been living among humans for a nearly a year now thanks to the serum. During that time, her good looks had caught the eye of many men. Some had gotten a date, some turned into short relationships. Nothing lasted.
Kevin is Lilia's current boyfriend, more or less. He is a marine biologist; they had hit off in part over a mutual love of fish. They have been on several dates, but they live seperately and the relationship is not too serious nor exclusive. Lilia's fascination with the human world and her desire to explore it further can lead her to seem distracted, flighty, or otherwise erratic.
---
They were standing in front of the door to Lilia's apartment, where Kevin had walked her after their latest date.
"I had a lovely evening" said Lilia. "I hope we can spend some time together again next weekend?"
"Uh, yeah, definitely" said Kevin, the disappointment a little too evident in his voice.
"You didn't have a good time?"
"I was just figuring you were going to invite me in."
"Oh. Well, no. It's kind of messy right now and I have to work in the morning."
"Ah."
They stood their in silence for a moment.
"I realize I may have given you the wrong impression" admitted Lilia.
"I just..." Kevin began, only to be cut off by Lilia grabbing him and pulling him into a long, deep kiss.
"Good night, Kevin. I promise I'll call."
Lilia slipped into her apartment, leaving a stunned and confused Kevin standing in the hallway. He certainly had never shared a kiss like that one with a woman who didn't invite him in. He shook his head and walked back to his car.
---
In her apartment, Lilia hurried to her secret stash of serum. What time had she taken the serum last night? She couldn't remember exactly. If she invited Kevin in she might not get a chance to get the serum before it was too late and she absolutely couldn't let him know she was a mermaid!