"While reading 'Kneeling In Doubt While All Skies Fall' I had the urge to read more fics where Arthur is turned in by Merlin's magic, whether reveal or not I don't mind!"
Arthur finds out about Merlin’s magic and finds himself turned on by the knowledge that Merlin could easily overpower him.
Tickle My Fancy
Merlin has had enough of Arthur bossing him around, so uses his magic to paralyse him and starts to tickle him, first with a feather and then his fingers, to teach him a lesson. When he starts tickling Arthur’s feet and toes he realises Arthur is starting to get very turned on, so he starts using his tongue all over Arthur.
The Light of a Thousand Suns
One hot day, Merlin’s magic is revealed to Arthur.
Pass the Time
Merlin gives Arthur what he needs.
With Thine Own Ardour Glowing…
Merlin has been avoiding having sex with Arthur in a desperate attempt to keep the magic secret… but of course that’s not going to work forever. Arthur eventually insists, and is horrified when Merlin’s reactions reveal the truth.
Hope those work okay for you!