WTH? You go to her and tell her that your friends don't understand this dance and think that she is cheating on you with her dance partner. It makes you feel uncomfortable that they think this. You've tried to explain this to them but they don't understand. You discuss this with her, make her understand the situation. If she has the tiniest bit of empathy and cares for you, she will most probably suggest herself to tone down the dancing in this company. If not, you can suggest it carefully. Continue talking until you reach a solution to the problem. The passive-aggressive approaches and manipulating you partner to feel insecure may work short-term but are very, very toxic in a real relationship.