If he calls me his boo?

I just want to know that if he calls me his boo does it mean we are going out? We always talk, he calls me his boo, and kisses me, but he hasn't said anything about us going out. So if you could answer it would help. And if you want more details, just ask. Thanks.

its not a long kiss or anything, at first it was a kiss on my check, but he moved to my lips, but its just a quick one that's it