No.... Never; they must have just been a rumour, bedchamber services doesn't always require servants to sleep with them, and the whole incident itself is a bit contradicting but for the matter of fact, shah amon himself is a dragon, that only ever pique interest in one and only human shah Na - in,(don't worry bro is loyal since he doesn't have that many emotions,or something like lust hovering over him ; he's built different)even if you ask the people who already red the novel or the raws they will say the same thing, I also heard about this matter from those people...
And also Gwen might not show it but he deeply despises amon from the bottom of his heart, he would also never sleep with anyone , especially with his enemy, just because amon is powerful and has higher states, don't think Gwen is lesser than him (my bro is also strong and will later show that) my bro only love his beloved na- in (good thing about this manga is that everyone is loyal,whether their evil Or not)

I just read this and I’m a little confused on the whole Amon/gwen bedchamber incident. I know Amon called Gwen to him but did they actually sleep together??