In the world of hentai.....it means exactly what it's name implies(please don't ask me why i know that...there are things one doesn't want to remember).
che so you asking when to run away instead of which one can called H~ gore, can't apprehend it giantess, beyond this cat mind super muscle x muscle.... some other niche kink like multiple boob, deformed body, snuff (beating and hitting but not cross da gore yet)
yeah, brain fuck mean literally fuck da organ not like concept such as breaking a mind~ there was doujin involve insect alien did that~
A male character or said female character's male organ is inserted inside the forehead of another character, typically a female in most cases. This is not a metaphor but a literal insertion. Do not speak of logic for there is none in the amazing world of H. Warning! You will very likely lose brain cells trying to comprehend how the action itself is possible and safe. It's not. (Double puns)
draw the line as in won't fap to it, or completely unacceptable? for me I'm okay for any fetishes to existence in H(as long as it's not real), but I won't fap to a vanilla yaoi, etc.
Were one draw the line in hentai......well, for me when there are the tags: guro, scat, ryona, snuff, torture i absolutely don't open(or make click) in the hentai work(manga, doujinshi, etc.) not even as a joke. However there are sites that don't post the tags unless one opens the hentai work...... In respect of futas....well, i don't like that kind of stuff though there are people that do.....so i believe is a matter of ones taste. Edit: Also source of many of my traumas because the cover some works(which have some or similar tags with the previous mentioned, there are also some tags which i don't want to see but they aren't as bad as the previous ones) are, too fuck*ng, explicit.
I don't read hentai much often but when I do read, absolutely never scat ugly bastard shota/loli torture/gore ntr softcore
There is no limit to H. When one draws a line in H, thats the meaning to being cultured enough to stop fapping to one you don't want to cross. Once you become a cultured person, you know you have already cross the line. Mine, i already accepted watching and reading so many fcked up H, after every fapping session, i bathe in my own sins and go back to the usual fap routine and vice versa. Thats how deep sht i've been in H.
I was actually thinking what it meant brain fuck... and by y'all reactions I really am simply gonna hyponize myself and not even think how the hell it's possible to brain fuck somebody. Anyways, here's my list on when I draw the line when it comes to H stuff: Tentacles (gives me goosebumps even by thinking of it, I just think of the germs and etc), adult + child, mom+son/dad+daughter, gore, giant, human + animal (literally a pet), anything futa related.... Well pretty much this for now. I am sure I have more to list.
Author Komekouji? Respect for his research into multiple breasts demon girls but sometimes he crosses the line...