Guys' dicks don't stay hard when they're being fucked in the ass.
Yet, in slash that's never what happens. When Clark or Lex are being fucked they stay hard and they come while they're being fucked.
THIS IS UNREALISTIC.
I don't know how I feel about that. On the one hand, I like feeling that a sex scene is "realistic" when I'm reading or writing it. On the other hand, I like guys coming while they're being fucked.
WHERE DOES THAT LEAVE ME?