What to expect with your first tail

[Elle]

He's a size 9.5 men's.... that's like a size 11.5 women's. I don't think toe-holes will do the trick for him.

Arion, I would just ask and see if you can get the Merbella fluke made with a rapid or cut-down competitor maybe? Seems like that would give you the best chance at "floppy" while still being large enough for your feet.

Arion's post wasn't there when I was typing but yes, an actually Merfin would be out of the question, unless she actually gets around to making adult sizes (they are actually made for children)
A competitor can be cut to look like a Merfin though. That seems to be what Raven has done with her tails that have that fluke shape.