I’m pretty sure it’s the lower part of the colon ╮(￣▽￣)╭
I saw a comment under "boundary of delusion" where the top penetrates that part as well explaining why, basically if something goes through that part entering the colon your body reacts to the foreign object as something that shouldn't be there, kinda like "this part is in danger" causing the person to have extreme sensory stimulation
thanks for the insight, guys. i feel educated af
and also, you're correct, just yaoi anatomy. not factual or smth
im stupid can someone pls educate me whats that thing called or is it just yaoi anatomy? when the dick is penetrating and it goes thru that little layer of skin (chapter 16) like wtf is that i need to know ive seen it in so many bls