Should I apologize for my flirtiness?

I was a little flirty with one of my guy's friends and I think I must have made him feel uncomfortable because he's kind of avoiding me...giving me the cold shoulder. My guy is not the jealous type, so there's no problem there. Not sure if I should just leave his friend alone and let him get over it, or send him a quick note, saying sorry if I made you feel uncomfortable. He's already ignored one text, so I'm kind of apprehensive about sending another one, but on the other hand, I also don't want there to be tension in the air the next time we meet. How would you handle it?