And basically this is the realization that just hit Usagi: this is what it’s going to be like for the REST OF HER LIFE. Because Chibiusa is their daughter, she is ALWAYS going to have to share Mamoru with her and ALWAYS have to accept that his attention will be divided and focused on Chibiusa. For all time. That’s a pretty heavy thing to handle, and againagainagain Usagi barely got anytime of having Mamoru all to herself before she was thrown into this family dynamic.

It’s basically a really adult feeling for a teenager to deal with. As I said, Takeuchi is probably riffing off some very real feelings adults have about their significant other after they have children (maybe feelings she herself has had)- the relationship can suffer because of the focus on the child, and that can cause an adult to be jealous of their own child for taking up their partner’s attention and wish things could go back to the way they were. And now Usagi knows what she’s feeling, but she’s not enough of an adult to deal with it maturely, nor should she be.

And again, though she has affection for Chibiusa at this point, she still hasn’t developed a strong enough bond with her to let her prioritize Chibiusa as much as Mamoru does, and balance out her feelings of jealousy.

(Also I find it sort of hilarious that all Mamoru can do to respond is say her name really loudly. Like “what is this I don’t know what to do I don’t understand words”)