No ... if you're flirting with someone it means you're attracted to them. If you aren't attracted to them, don't flirt.
If someone were to start flirting with me, I'd think, "Oh ... this person must find me attractive," not "Oh, this person is just getting his/her jolly's off at my expense."
If you're going to flirt with someone, be prepared for them to take it seriously.
That being said, whats your sign?