Why is VIRGO acting this way?

I'm a capricorn and he is a virgo. We met a year and a half ago and were at first, the greatest of friends. We just started revealing to each other that we "like" one another. We've even had sex a few times.

The thing is though, I find it hard to read him. Some days he's calling me to talk to me and some days I don't hear from him at all. I messaged him today to let him know that I was thinking about him and I got no reply back whatsoever. He usually doesn't ignore me but recently he has seemed a little more distant.

When and if he reaches out to me again, should I answer him back or ignore him like he did to me? I'm kind of upset because one of my biggest pet peeves is to be ignored and it's not the first time he's done this. It's making me question why I even opened up to him about my feelings. Your thoughts?