Flirting or being nice

Now I am a nice person and I have a tendency to smile and joke with people that come into my job. And my coworker (He that shall not be named and u know who u are) says I flirt and calls me and my sis a “snake charmer” But I don’t look at it as flirting. I guess my personality is considered to be flirtatious. But I don’t see it I mean let me give the back ground on this. Alright I’m working and a guy signs up to get on the computer and his turn comes up and I call his name and put on. And then the computers are closed down and he comes out and gets ready to go home and I’m doing the closing announcement and I mess it up. And he comments on it and I smile and laugh and say yeah I did mess it up. He smiles back and jokes with me about it and I smile and laugh and I didn't think i was flirting i just didn't want to be rude and tell him to shut up. So I don’t think I was flirting, I think I was being nice. And the coworker says i do it all the time and i just keep on reeling them in. But i don't see it that way.