I have always been confused about this, but when does it become flirtation?

People sometimes say that I flirt with someone but that is not what I want to do. I like teasing people and having a good laugh but I don't want it to turn into flirting. Because I'm not interested in sex/women/relationship, at all. So I don't want to give off the wrong signs to people. Or is this more subjective to the receiver? One might think it is flirtation while the other doesn't?

Anyway, I'm just trying to make it technical so I can easily adjust my behavior around people.