Float on your back and have Xiarel ride you

You push off and lie on your back on the surface of the water. Luckily, you don't have as much muscle as a normal orc, so you are in fact able to float. Xiarel lowers her box onto your pole and wraps her legs around your hips.

With no leverage, you're not able to thrust upwards. But Xiarel simply flexes her internal muscles around your shaft. The feeling is very pleasant, and you lie there, with her on top of you, and enjoy it. You gaze up at the sky as Xiarel gradually works herself to an orgasm. She smiles as she looks down at you.

"You feel wonderful inside me."

"You feel wonderful wrapped around me."

It takes longer than usual, but Xiarel eventually, with her fourth climax, drains the cum from your balls. She slides off you and you return to the edge of her pool. The two of you snuggle, you holding her slender body, for a few minutes.