How would you feel/do if you're loving for someone that unfortunately married?

One way to make somebody think just a bit harder than they otherwise might about some sort of a questionable wedding is to let them listen to the Big Bopper's Wedding aka the flip side of Chantilly Lace:

http://www.youtube.com/watch?v=XPw9OBC28dA

This man is not free to love you.

If he is flirting with you, then he is not an honorable man.

Fall OUT of love. It can be done.

Go on with my life - this person is already taken.