If the guy's foreskin retracts when he is erect, he does not have phimosis. I have a friend who tells me that his foreskin never retracts, even when he's completely erect and even when he climaxes. (Years ago I saw a video of a guy with phimosis, and he and his wife seemed to not have any problems at all with it as she sucked him and as he fucked her.)
