Was this really necessary? I know it's hot but the whole scene shouts "FAN SABISU!" it feels like it broke or cracked the 4th wall
Also, where are you hiding the Lesser Grail?
It is fanservice, I'm not going to deny that, but it's not pointless fanservice. Caster is trying to break Saber's will by "defiling" her noble character. It's basically a torture scene without any blood.
If Caster was more vicious, she would've summoned faceless bald men to take dibs on poor Saber. Also, is there a doujin for that? Time to find out.
So? don't tell me you would pull a FE:Fates on us with anime anon cause that's bullshit.
Or what? do you think the hordes of chunni seibah-obsessed nipponesse didn't want this to make the cut? Hell, it's probably the one reason why they were watching the adaptation that has nothing to do with their chosen Goddess .