I'm sorry but seriously people!?! two of the catigories it is under is ecchi and smut. Also the title is "Xxx Lesson" I'm sorry but I'm pretty sure xxx is a replacement for the word sex. I'm sorry if you thought it would be all about love but honey love doesn't always come first. Anyway, who care if it lacks character development; it is a story about sex or more importantly, lust turning into love. Also, she isn't a whore for wanting to have experience.
Although I can see where bs is involved. He left her so the kid can have both parents and so a woman could have support. He was doing the responsible thing. Wasn't what was in his heart but duty over heart.