nitpickery to the max: jaw outline on the guy bands, just take TWO PIXELS away.
The dude's upper arms are too heavy that make his forearms look small. Their length is right, I'd just shorten and slim the upper arms a bit.
You could aa the sideneck (white area) under the flowing hair but I guess you know that. There's some banding on the right shoulder where the AA lines up, generally, be warey where your shading lines up to a contour shift!!!!!!
On girl, the shading on the right shoulder is too strong, segments the arm, looks like a toy figurine arm instead of a real one. I realize and appreciate muscles are cool, but I'd take away THREE PIXELS there too.
Love the jutting hip don't mess with it.
I like the designs of both hugely, I want to see the background they're on, don't be afraid to use a fuller palette.