Help with boyfriend

Okay first off I love my boyfriend and he treats me very well. The  major problem is he doesnt know when to stop a joke or when he says something that I am insulted by he doesnt get it. He does this very frequently and is totally oblivious. I am not super sensitive and sometimes let it go but its hard because hes perfect in every other way. Before we met he watched lots of porn/movies. I truly believe that this has started to affect our relationship and it needs to stop. Has anyone experienced something like this??