For me it's when the uke is confused/hate/reluctant to be on the bottom. Because usually when the uke is like that, the seme will push the uke until he's willing to submit -_- The highschooler side couple in Honto Yajuu is a good example of that I very much prefer a gay bottom uke that's not afraid to bottom and an understanding seme please :)
Ir depends on my mindset going into the story. If I know it's just a random hardcore porn, I don't mind rape at all. If it actually has a plot, rape is a big turn off. Pedophilia and incest always gross me out tho reply