[It's not like he's about to prostrate himself for this--he's a prince!! He's better than that!!

On the other hand.

He's the prince of a country that presumably cares a fair bit about dragons considering their bloodline and general capabilities, and Leo's the more well-read of the Nohrian siblings as it is; he hesitates for a moment, uncertain, before he briefly bows his head.]

... I apologize for my trespasses.

[Of all sorts... that's not what he wanted, of course, and trespassing on holy ground generally goes very wrong for most people.]

That was not my intention. ... As soon as I have found my way from this place, I shall leave you to your peace.

[He's grumpy, after all, but not unreasonable.]