I'm at a serious cross roads, and need help

Has somewhat sexual content, so trigger warning or whatever those kids call it

Spoiler

I have two friends, both of them girls, one of them might have feelings for me, but that's irrelevan, let's call her the tsundere. The other girl, I've known forever, oll call her tge yandere, she has a girlfriend (biological male), confusing yes.

The setup: so the tsundere is very territorial over me, but I don't really care. She gets a little jealous when other girls talk to me, but she dies that with most of her friends.
The yandere girl likes to touch people, not always sexually, but usually her girlfriend, me andbthus other guy. I don't get uncomfortable because its usually like hugs or puting her arm around mine, that stuff... But today... She touchedy bottom with out consent. We just laughed it off, and stuff, and I am concerned now.

The problem:
The tsundere and I has talked about this incident before it happened, and she said she would, and I quote "emotionally destroy the yandere". Her girlfriend doesnt care what the yandere does, so idk what will happen. I haven't told the tsundere cause I'm torn between telling the truth to her, preserving fruendship between the yandere and tsundere, and keeping the yandere and her girlfriend out if any trouble

So what do? Has anyone else been in such an odd situation? I'm lost and I have like a week to resolve this

 

The tsundere is overreacting. Wow, that is over the top. Also, the yandere is a bit... I don't know how to describe it. Both act inappropriately. So do the thing that will impact all of you the least.
I suggest talking to the tsundere. If she's territorial over you, I think you can request her to not emotionally destroy the yandere. She's the main problem here. Try to negotiate before forwarding it to responsible adults. This might descend into bullying if she goes on to hurt her feelings. Do it in private.
Next, the yandere. Tell her to stop touching you. It is the cause of your problem here, so yeah. Do it in private.
Ask your friends to watch the two in case of emergency.
I hope this helps you.