How much does hardcore sex hurt?

It depends. The term "hardcore" means that the ACTUAL acts of penetration, ejaculation,etc...are shown in pornography films. "Softcore" basically just provides the 'idea' and not the visual of individuals involved in various sexual acts. So if hardcore is used as explained in the context above, then no it doesn't/shouldn't hurt. It means you are actually having sex and not dry humping. Now, if you mean hardcore in the way of whips, chains, ball gags, hot wax and bondage....then yeah, that might hurt.