Sadde knocks on Isabella's door at 7PM sharp.
Sadde's apparent athleticism is entirely an artifact of years of shapeshifting. She actually can't swim very well, so she mostly waddles along inexpertly, chasing Isabella.
Isabella reaches the other wall and pops up. "Do you not know how to swim? You didn't say when I suggested swimming."
"I know enough to play around and get places, I can't exactly do competitive swimming," she shrugs.
"Swimming's the only time I get to be faster than anybody," laughs Isabella, and she zooms back in the other direction and pops up when she reaches Sadde. "I'm not even that good but still."
Sadde kinda follows! She lacks technique but once she's got going the artificial athleticism makes up for some of it. Not enough to keep up with Isabella, but.
Isabella knows the basics of several strokes and can hold her breath for a pretty long time. And grab Sadde's feet and yoink.
Lots of splash! Sadde can also hold her breath for a while and attempt to yoink Isabella, mostly failing.
She gets an Isabella, caught. An Isabella who kisses her, squishing Sadde between herself and the wall of the pool.
"Fondue." Pause. "Alex got me a little tiny fondue pot expressly so he could tease me about feeding you chocolate covered strawberries."