In general, don't invite strange ladies with partners. If you all know each other, you can simply say, sir, may I ask this lady to dance? Or: Sir, can you ask your friend to dance? If you are all close dancers you know, you'd better invite them first! Jump tired, sweat, and then let go!
Note: According to international practice, two ladies dancing is tantamount to announcing that they don't want to invite any women to be present, which virtually shows that they are gay. The two ladies should try not to dance, especially when there are foreign guests, so as not to cause misunderstanding.
From the point of etiquette, a woman should not refuse an invitation from a man. If the lady doesn't give you face or politely refuses you, stop in time and don't force it. When people don't know each other, women will instinctively accept the invitation of men in the order of "first come, then arrive, first kiss, then sparse, first handsome guy, then old man, first gentleman, then dancing hooligan". If a lady doesn't give you face or politely refuses you, then she has to think about her own reasons. Why are you disgusted with this lady? Disdressed, unkempt, dirty, ...? Or didn't take a shower before dancing, didn't wear clean clothes (no matter how smelly the new clothes are), didn't use toilet water, or didn't eat gum, … and so on?
Suggestion: Don't drink white wine before dancing, don't eat unclean food, and it's best not to smoke, which can reduce the odor and try to win the favor of women. A lady is a mirror of a gentleman, and rejection is a reminder of a bad mood. Men should pay special attention. The ball is an arena to show gentlemanly manners and win the favor of women. Men's untidy clothes, bad breath and body odor are important factors for the failure of the invitation to dance.
When dancing, the man gently supports the partner's waist (slightly higher than the waist) with his right hand and holds the partner's right palm with his left hand. Especially when spinning, the man must dance steadily, coordinate his movements and enjoy the beauty of the waltz with his partner. In case a lady is found dizzy, a man must be a "flower escort", escort his partner back to his original seat after a piece of music, and then invite another lady after thanking him politely.