I actually don't like that line at all.
It to me is a cop out. Like, I will have sex with you but I am not interested in being your boyfriend... I like you though..
He either has baggage in my opinion, and is to "scared" to enter a relationship or he is having fun being single and does not "want" to enter a relationship.
The bottom line is, if you are after a relationship, let him go. Move on, and find what you have been trying to find and deserve.. He's not the right one for you.