Exactly! !!! You say you love him but then you sleep with someone else as a substitute cause he won't go all the way?
Once again Tsubasa was just 16y/o having sex with him is still a crime plus his lover considered him a bit immature for a sexual relationship...
Precisely.It was Eiji that wanted to wait to have sex for Tsubasa's sake. Eiji, then would have had to be celibate for four years. That's like taking a starving man to a steak restaurant and only allowing him to eat salad. By foregoing monogamy for that time, Eiji was reducing the risk of physically hurting or emotionally scarring Tsubasa and becoming a criminal.
Exactly, I wouldn't expect someone to be celibate that long. It's unreasonable. Same reason super long, long distance relationships never pan out, because you can only be sexless for so long once you've already had a taste of it...
Actually it would have been 6 years if he waited till Tsubasa was 20, which is the legal age in Japan, (f they were in America it would only be 18), and they'd already been dating 2 years when the story started and he said he was 16 so...

Whats the point in dating someone if you are going to cheat on them, so what he wasn't going all the way with you, that's no reason to sleep with someone else! You were still getting something, right?
When he Tsubasa found out that Eiji was sleeping with others why with him, that part of the story was just stupid how it turned out. Even for a manga.
After all that was over with and they were a normal couple with no cheating anymore, they were a pretty cute couple.