Why does it bother me when he doesn't text back?

I was talking to my boyfriend and he just stopped texting back. He really doesn't have to text me back, I was just wondering why does it bother me, does that make sense? Because when i read it out loud it sounds weird...

?2017-04-17T22:54:29Z

Obviously because you care about him. Duh!
You feel like he disrespects you when he forgets to text you.
Beware he might be playing you