Help with my crazed for boyz friend?

lets make a very long story short. my friend (girl) she likes one of my friends (boy) she got all ticked off when i went to a cookout with him. like i said, he is one of my really good friends. she said how would you feel if i "hung" out with ~blank~ i not telling~ and went to a 'grill out' with him i left. what do i do now? she has dated many boys fyi