Since the glasses kun/ morishita has low self-esteem or inferiority complex, he only seduces guys whenever he feels they might get snatched by someone else.
But overall I don't think there was any love between yoshitake and kawamura when they were in high school...honestly even when they met after 8 years, the feelings of yoshitake for kawamura was so out of the blue and remained unexplained.
Anyway I don't think he was the kind of seme who is in love with someone else and at the same time have sex with others....because 1:there were no such feelings as love when in high school...2:he was basically having a relationship with morishita/glasses kun....morishita said that they broke up later ...well,morishita is a shallow character who only looks for superficial pleasures and a simple black and white relationship
24 years old Yoshitake's is more aggressive than the 16-years-old Yoshitake's? Huh, why did not you make a move from the start to Kawamura? Why ??
I thought Yoshitake fell in love with Kawamura since they were in Aviation school. Yoshitake slept with Morishita just lust, no love at all. But unlike Yoshitake, I'm sure Morishita loves Yoshitake because he felt jealous of Kawamura (he gave Kawamura porn magazine). so do not despise Morishita too much.
After all I really looooove Kawamura character the best. He such a caring guy and knowing how to make his lover feel better. Morishita couldn't do it, that's why they were broke up.