Head cannon: kim being jealous cause now that Trini is out in school (assuming she did that) girls are hitting on her and she can't do anything because they're not dating (just acts overprotective), so onetime she does and Trini is like relax dude I'm totally into you.
Ignore the fact that I’ve never actually felt jealousy lmao.
Listen, she’s happy for Trini. Kim’s so glad that Trini was ready to come out, that she’s no longer feeling the need to hide that part of herself. Honestly, Kimberly is absolutely delighted about that.
The problem, though, is that now every wlw is hitting on Trini. At first, Kim brushed her annoyance and intense need to tell them to fuck off as simply looking out for her fellow Power Ranger. Of course, such a lie can only last for so long.
Usually, all Kim lets herself do is be…slightly overprotective. She’ll walk in on some girl flirting with Trini and she’ll say some shit like, “Oh, hey, Trini! Jessica, how nice to see you. Weren’t you supposed to meet Jake earlier? He’s looking for you.”
And, honestly, it’s pretty pathetic, but at the very least, it works. Most of the time, all Trini will do is quirk an eyebrow so Kim likes to think she’s being subtle about it.
One day, though, Kim can’t take it. Trini spends the entire day at school surrounded by beautiful, and most importantly, sapphic women. There’s no way she could get them to leave without being overtly suspicious and so Kim spends the entire day stewing in her annoyance and wallowing over her situation.
When the bell rings and the two of them are walking to the spaceship to train—Trini finally without her gaggle of annoyingly dumb fangirls—Kim explodes.