I'm guessing you're guilty because you are either attached to someone or full-fledged married. It's good that you're feeling guilty, because that's an important self-realisation that you might have taken things a little too far. I only believe that there are 2 types of flirting - there is the friendly kind where you do it to boost another person's self-esteem or maybe even yours (because you want to know that you are still attractive). Friendly flirting has boundaries and knows when to stop. Then there is the kind of flirting where you have the intention to take things further with another woman. If this is the case, I urge you to consider your relationship status before you indulge yourself further. In this case, you might want to consider being single to engage in serial flirting habits.
We are genetically wired to be attracted to other human beings. Even the most faithful ones among us will occasionally succumb to the temptation to flirt with another person. Go easy on yourself, friend. If you are single person, you may want to see if the “connection” is reciprocal. If you are in a committed relationship, remind yourself of the commitments you made to your significant other. Guilt helps us maintain personal responsibility. Too much guilt, however, is paralyzing.