So that people understand - "sexual" as a root toom is referring to one's sexuality - so to say "a" and "sexual" means to not have a sexuality. That means that you are not attracted to any person sexually -for some, sex does indeed feel good - just because you aren't attracted to other people doesn't necessarily mean that the act itself doesn't feel pleasurable. (That's not how things work) Some asexual people still have sex, because A) It feels good, and B) because it makes their partners happy. However, some asexual people just.. don't feel good when they have sex - through a combination of neurological and sometimes biological factors.
This is just mopping up some misunderstandings.