I'm very much into being fucked but often have a hard time getting my hole to cooperate with my mind.  With any luck some of you more experienced bottoms will be able to help me take a man like a pro  
  
Being new to this and having very few friends to discuss it with, I'm not sure what it's "normally" like to take a cock.  Should I always expect an incredibly acute burning sensation as the man presses into me?  I've had to stop guys sometimes due to the pain, and have only been able to take a couple loads (which I love to do)- other times I've had to stop my top prematurely.   
  
How can I train my ass or brain to better accept a man?