Responses
It's true that Sakai was feeling slightly insecure but the major reason for his decision to break up with him was for the fact that he felt guilty from taking away his "happiness" of having a family since Shizuka was disowned and kick out once they family find out he was gay. Although the decision was a bit selfish, I think Sakai only wanted to see Shizuka happy. Overall I love both characters they were just perfect for each other. I'm super happy that Shizuka fell in love once again with Sakai, that shows how serious is about him. Sakai doesn't need another I love you, Shizuka has already prove how much he loves Sakai, not once but twice.
If I read sentences like: "it's for his sake/ own good"; "I don't want to take a normal life away from you"; "I just wanted you to be happy" etc. one more time, I'll to throw my tablet against a wall. Seriously! A grown-up should be capable of deciding for themselves, what they want and who they're happy with. I can understand that one might feel insecure but these insecurities should be disolved by discussing them with your partner and never by simply running away.
Rant over.
I still like this manga because, let's face it, Shizuka is perfect ;)