Responses

I think it’s not much “fantasise” but rather an intrusive thought he got after he realised the real sort of “relationship” he got with the bottom. As you can see, he’s having a sort of break, so he probably didn’t mean to really think about that but rather it came to him as a violent outcome, just like sometimes after so much anger, some people might get the intrusive thought to physically react against an outsider threat, whether is against yourself or a third party
I kNOW seme didn’t just fantasise abt giving Uke an anal prolapse