I was talking about having a bad attitude during the dance to notify you don't like your partner. That's in my opinion terrible. A no if said kindly (don't have to be necessary with an excuse) will be accepted the majority of time. It may hurt the person feelings for 30 sec and then he will find another partner and will forget about it. If you say no a second time he will understand and won't ask again. We are all adults and an adult should be able to take no as an answer or that persons had some issues in terms of parental education. If you honestly think you said no nicely to the toothless guy, that's his problem how he handle it. The constant no with lame excuses or pity yes with passive aggressive attitude behind or even the absence of answer as I experienced it recently in Croatia (in the bachata room if I remember) doesn't elevate anyone. I personally observe how women reply to demands whether it's a yes or a no and their attitude during the dance and if I don't like what I see I just don't ask.