Most Helpful Guy
he is probably talking to other girls as well in case you leave him. It sounds like you are having fun but by taking things slow and not fully commiting to being his girlfriend, it is somewhat non commital at this point so, why he is probably giving you most of his attention, he still is talking to others to keep his options open because there is no official commitment yet.
If it bothers you, talk to him. If not hold your tounge and maybe start warming up to moving this relationship a bit faster.
Most Helpful Girl
If you want to take it slow but be exclusive at this point you should just talk to him... no point wondering - being direct best way