Reasons why he may not have responded to you, take your pick:

1. a He forgot to

1. b He forgot, then when he remembered, it was too late at night (because he knows your bed time)

3. He got side tracked with other things

4. He doesn't have time/is in the middle of something

5.a His phone died

5.b His phone died and he can't find the charger

6. He lost reception

7. His phone is off or he's sleeping

8. He doesn't have his phone with him

9. His friends stole his phone

10. He's thinking of the perfect response

11. He's too tired/sad/not in the mood to respond

12. His phone got taken away
SO DON'T BE OFFENDED
IF HE DOESN'T REPLY