This looks similar to something that happened to me...my best advice is when you're around him, be yourself, and if you think of something either interesting or funny to say to him then you might be able to get a conversation rolling. Good luck! ^_^
Does he flirt with you? Does he flirt with other girls besides you? I honestly hate when guys AND girls flirt with everyone, it's annoying and it seems like they want attention. Be careful of falling for him to fast.