maybe he's over it. maybe he's found somone new. Maybe he's frustrated about something. Who know's. why don't you just casually bring it up one day
it could mean he wants some space..
and maybe to try being just friends .. not "friends" for a bit...
guy don't understand "friends" it she either likes you or your a friend no inbetween. I am in a situation right now where she sees me in between the two and it basically a 24/7 mindf*** because she goes hot and cold. If I am flirting less I am either losing interest or think she is same with moody and being distant