The thing is, Laurent knew he was beautiful. Throughout his life, soldiers, suitors and people of all kind wanted him for his looks. They treated Laurent with disrespect, assuming he was only a pretty face and completely disregarded that he was an actual person who shouldn’t be objectified. In fact, Laurent used his looks as a way to manipulate Torveld into accepting the Akielon slaves. He didn’t care about it because it was merely another tool at his disposal.

This all changed when he and Damen began to fall in love. Remember the scene in King’s Rising where Damen said that Laurent was attractive? Laurent’s amusement was because his appearance was the first thing people noticed about him. And here Damen was, explicitly mentioning that fact after they had sex. After Damen had expressed his true feelings for Laurent.

Damen was obviously physically attracted to Laurent, but he came to know his mind, his heart, his personality, and ended up falling with the WHOLE Laurent. Laurent was no longer just a body to be admired and used, but was a person to be cherished and loved for who he was.

So yes, Laurent knew he was beautiful but with Damen, Laurent felt beautiful.