Friend's boyfriend keeps flirting with me...what should I do?

I have been in similar situations like that before. I used to be shy, but now I have almost fully grown out of my shell. I did have a fling with one of my friend's crushes (not boyfriend). nd it felt GREAT! Live your life for once. Don't sacrifice your happiness for someone else. I did it for years and I regret every time I did it. Live your life, take chances, and win!