Totally agree with you man. And the sex friend just gotta tell you how they fuck better than you too. Hate that last story.
I guess you did not understood the story, Ho-chan no longer had a sexual relationship with Hinohara, they broke up on the first story when the captain falled in love with Asou. Even when they no longer had sex they will still be friends (thats what sex friends means after all), and the captain was just teasing the new lover who had gotten the heart of someone who did not believed in love. As for Kouji not being good in bed well I guess he is inexperienced as compared with his sex friends but he Ho-chan stated that he likes that because he is satisfied making love with his lover and not having indifferent sex with a sex friend and that was the difference...
i would never stay w someone who still kept a sex friend on the side, or was a little sh*t, like that last story telling his lover he's not that good but he still likes it(that's a blow to one's ego, especially a man's). ugh but it's a manga, gotta have conflict lol