Clear, assertive leading is not to be confused with being macho. Good tango, either done by a leader or follower, is largely about making the experience enjoyable for one’s partner. And caring about what onlookers think isn’t such a priority.
Being macho, however, is the exact opposite: It’s about craving an audience while mostly exploiting the partner as a means of gaining said audience. A macho leader often attempts this by grabbing his/her partner and jerking her around the dance floor like a mop (I’m sure most of you readers have seen this for yourselves, or have unfortunately been on the receiving end of it). And whether other dancers are in the way or not is quite irrelevant.
The macho leader doesn’t (or never will) understand that narcissism is not the same thing as being confident or assertive, let alone an indicator of effective tango dancing.
So don’t feel bad about turning macho man down for a dance – it’s for his (and your) own good. With enough rejections and a desperation to squeeze someone, maybe he’ll finally leave and go home to his teddy bear.