What does it mean when a guy traces patterns on your skin with his fingers?

I was making out with my (only) FWB the other day, and while we were kissing, he would trace patterns with his fingers on my stomach. It was really cute, but I'm a little confused if it means anything or is it just a subconscious thing? And after we were done messing around, he would kiss me on my forehead. We just became FWB the other day. Thanks guys I'm just really confused!