Currently, no, not with anyone other than the one I love. Though even at that, there isn't a great deal of need to flirt with your partner, you both already know that you have feelings for each other and from experience, I know that 90% of flirtation is to achieve the knowledge as to whether the person is attracted to you or not.
But, when I was younger, or at least when I was single, I wasn't one for flirting to be honest. I've always had a good social life and I've met a lot of girls and I'm experienced in the field if it's not to brass to say, but, I've always been one for romance as opposed to cheap flirting or cheesy pick up lines. So I was never really a flirt per say. I think I'm much more of one online however, mostly because I don't take it as seriously, and I just find it pretty funny, as do most people who flirt online that I know. As for being flirted with, I generally do if it's online just because it is funny and it's not serious, though in real life situations, it'd take a lot to convince me to flirt back. For me, unless it's not going to be a relationship, I wouldn't flirt back. I like to get to know people by other means, by simply talking to them and ever so subtly getting closer if attraction lies beneath the exterior of familiarization. But to sum up, I can be an awful flirt, but really, I'd be too far pushed to say I'm serious about it.