The way he suddenly filled her elicited a half-sigh half-moan from Luna and she pressed herself down onto him as far as she could. With a hand on the table nearby to steady herself, Luna leaned back to improve his angle and to better show off her body for his gaze as she took control of their movement speed.
When Luna pushed herself back towards him and away from the table, it was so she could kiss him again, messy and hungry and a little hard to maintain against the tempo of their hips. Luna was willing to do her best though, because why would she want to stop kissing Merlin?
There was plenty of gods that Luna got sent along to entertain, and for the most part she was good at finding the enjoyable parts even in the time when she'd prefer to be at home in bed, or curled up with a book. Luna's life was so often an all-you-can-eat buffet of genitals but sometimes a girl just wasn't hungry.
But when she was with Merlin, Luna rarely had to go searching for some tiny point of enjoyment, rarely had to fake her interest. With Merlin she was almost always interested.