Harley & OPEN
This doesn't even strike Harley to be one of her red flags at first. She just really loves the sounds and when she spots one of the mermaids? That's it. Harley just has to meet one. Maybe braid their hair?
Only when she hits the water and goes "Wait, what the heck am I doing? This feels like a trap" will she snap out of it. Too bad one is pulling her into the water and snapping at her. "No biting! I ain't into that!"