I agree with the above poster, I feel everyone else has jumped to conclusions.
His priority does seem to be sex, but that doesn't automatically make him a jerk.
OP, did you tell him that his teasing was hurtful to you? If not then he may not have even realised it, and it may have even been a way of him communicating that he actually likes you (which would indicate a lack of maturity, but some people show it by teasing nevertheless). I get the feeling that you haven't communicated this to him, though I could be wrong.
If you have told him, how did he react? Did he take your feelings into consideration or belittle and dismiss them? Did he stop saying hurtful things? This would be the actual determining factor of him being an insensitive idiot or not.
You said he's a nice guy and that he has little experience with girls, so perhaps it's just miscommunication.