@Sarge688
Actually it seems that Fate/Extra only implied it by saying a fictional story like that exists in-universe, but doesn't actually confirms they indeed switched places. Fate/Grand Order decided to ignore it and outright said she was a woman.
Chika be like: Oh yeah imma... just yeah.. fuck it xD. My Fave ship is Chika x Riko, BUT I can't judge other people's ships, but I like this, it's pretty good. And do girls normally bath together, I think it's normal since in Animes girls bath together xD and the new Even grab boobs.