Most Helpful Guy
He has probably met someone. I would just ask something like, "Hey, you're not on as much as normal. Did you find a girlfriend or something?"
Most Helpful Girl
keep this rule in your mind: if a guy pulls back, you should pull back too! maybe he just needs some space and by chasing him (yes even asking is chasing which can even lose you your dignity) you will suffocate him! he either wants space or he lost interest, either way you should avoid looking needy at all costs and pull way back! if he comes back with a good explanation then great if not then its time to say goodbye!