Okay here's my guess: Watanabe has an ex-crush or ex-girlfriend from middle school that she fell out with (thats who was texting her) and so she immersed herself in the world of yuri as a way of escaping and deflecting from her own sexuality, vowing to "never have a 3d love again" and so she's gonna try to distance herself from Yoshioka out of fear of loss again.
yo I think you were right
Probably in the ex crush but instead of getting yuri as a way of escapism her ex crush taught her the ways of the yuri
I'm suspecting something a bit more bitter than that, where she was told a "mob" girl like herself could never be the protagonist in Yuri and could only ever be an observer, something along those lines. Which is why she seems to reject the concept of another girl loving her.
^^Oh yeah there were numerous R34 works of all of the new characters in the trailer the day it released, including this one. I'd say it's basically tradition at this point, where memes like this are common haha
Honestly this chapter was still on the very tame end of monster girl shenanigans for me, so I didn't even bat an eye and I simply thought the chapter was amusing haha