@blablablub because ritsu cares about leo and doesn't want his pop to do something terrible to leo? This is quite common in manga. The other pattern is "this is my problem, I won't bother others with my problem". But it's clearly not that.
@KipTheGamer when the topic of a manga is centered around taking care of children, they need to add more and more elements to keep it going and that often ruins the manga. That kind of thing should be done not as the main theme.