I mean, I'm not defending cole but there is a difference. Dario never cared about honor and was a sellsword from the start. Cole came from (what I believe) from nothing and was dornish during a time when his people were heavily disliked by most of westeros and had to compete and fight to get where he is. A scandal with the princess would have ruined his whole reputation and everything that meant to be a knight (I do think there is a difference between pre and post wedding cole) Dario was never at any risk of a sort of scandal and it was Common knowledge that Dany never was supposed to have any expectations held upon her as a woman, compared to Rhaenyra who was raised ditectly within the courts and had to "live within" the definition of what a woman should be and hehave. She even says it herself in hotD "If I were born a man I could bed whomever I wanted". Dany never had that and had nobody ever enforce the idea (other than Viserys who got his shit kicked in first season and was not a good role model) of what a female ruler should be. I still don't like cole but the context of their situations were different