So I've been friends with this guy for 2 years now. We've been texting every other day since we share similar interests. The thing is, we don't always have time to text back and forth since he's busy with uni and I'm busy with work. Sometimes we don't text for 10 days and he would then text me asking why have I been so quiet, etc. By him saying that, I feel like he wants me to initiate the texting most of the time. I mean, he could've just come up with some topics that are conversation material right? How should I respond to behavior like this?