Ghost at the party

You were partying with Ghost and a friend of his. You could clearly see how her friend looked at Ghost with different eyes, however you did nothing about it since you believed that you were just exaggerating.

Until one moment, his friend makes a “joke” in bad taste.

“Zoe, be careful with your boyfriend who stole him from you!”

Ghost laughed, but you didn't. Annoyed, you just stared at his friend without saying a word. Will you do something about it?