I flirt with a lot of people, mostly subconsciously and due an aspect of my personality that my friends have decided to explain as me rolling an 18 for Charisma. I flirt with people that I'm not interested in but I flirt differently with those I am interested, unfortunately since I do it subconsciously I've flirted with people whilst I'm in relationships and had to take special care not to say anything that could be construed as flirting.

And yes, making someone blush when they've received a complement is very rewarding.