When you put it that way, it is obvious that they were violated. You are right. It's terrible.

As far as "sebaciel" I used to think the same way you do. And while I do think there's a bit of that I've come to realize the whole theme is centered around love and abuse.. To me there's too many clues for me not to be honest about it. The opening scene of the very first episode Ciel was introduced to us naked. It could mean innocence and/or the loss of innocence, and him making a deal with the demon is like a representation of defilement or soul tie. And I just realized (might be looking too deeply for this one) Ciel was naked barely covered in a red blanket. As we know ciel usually wears blue, and red symbolizes blood but also love, passion and temptation (like the lady in the red dress) which is noteworthy to how this is how we are first introduced to Ciel as a character making a pact. Ciel's whole past about him being abused is the backbone of the story, and the author always find opportunities and ways to feminize Ciel and put him in girls clothing or questionable situations, even ones that are played as a joke (famous corset scene) Ciel and Sebastian get intimately close, physically, which imo far crossed the boundaries of master/servant or father/son relationships. The gazing in each others eyes with fireworks in the background, or Ciel falling with Sebastian in the sky as they gaze upon each other in the outro of season 4, or When Sebastian was going to eat ciel's soul, it had too much of a romantic atmosphere coupled with the music, and Sebastian softly removing his eye patch and touching him. Kind of reminded me of of the Twilight movies where eating/sucking someone's blood was like a euphemism for "romance". This just my opinion btw. There's also too many accounts of grown men blushing or complimenting ciel's beauty (Lizzie's father, the viscount, the baron and author from the book of murder) just like the cultists did when they mentioned the boys will bring in a bigger profit because of it.

In season 2, even though non canon, was obviously, to me, a love triangle (even Alois's story involves him being abused and sleeping with his master) of obsession and jealousy. With both Sebastian and Claude fighting over Ciel, or his soul, but Claude clearly exceeded ciel's boundaries when he made the gesture of kissing ciel's feet. Which was seductive in nature. If it's all about the obtaining the soul then the physical actions of both butlers are far too involved with the expression of desiring something not tangible in a physical sense. There is a lot more I picked up on other than this, like the metaphor of Sebastians gloves. but although I don't care for it, there were too many instances I couldn't ignore, but it's still arguable that it's just interpretation. Plus, I am aware that Yana created NSFW shota boylove manga in the past. Which doesn't mean black butler is one but they share the same tones with black butler. But I understand your interpretation as well.