When I read it I thought that Harry still thought that Ron was jealous of him, for being the one everyone knows, and the hero, while Ron was like the side kick, and just "Harry Potter's friend." With the insecurities of being a teenage boy, he was embarrassed by Draco getting the best of him, and after they had the tiff with GOF, Harry was probably felt that Ron would tease him about Draco getting the better of him.