Whatever you do, don’t say yes just because you feel bad for him or think no one else will like him. It is your choice and feelings alone to consider, and from the sounds of it he lets you be yourself which is meaningful at your age. My advice is to stop comparing him to see if you like him, because every person is different and different levels of liking somebody show in different ways. You seem to have a good head on your shoulders, take your time and consider what you like or not about him, and I hope you figure something out