Male privilege is “I have a boyfriend” being the only thing that can actually stop someone from hitting on you because they respect another male-bodied person more than they respect your rejection/lack of interest.
The Sociological Cinema
There was actually research that was done that found that women who used an “I have a boyfriend/husband” excuse to reject unwanted sexual attention and harassment by their bosses were more likely to be left alone than those who used any other excuse (including “I’m not interested”)