without making assumptions about his level of attraction to you. (I mean, unless he has told you straight out that he is interested in you.) Maybe he is sweet and awkward and shy, and whatever intensity you are picking up is his anxiety about talking with someone, and not sexual interest.

On the other hand, if he has explicitly told you that he’s interested, just be up front. Say something like, “I enjoy our chats, but for me our chemistry is more platonic than romantic.”

Just one suggestion.