It is such a crucial point to mention and it seems like in this day and age I would not have to mention it but the number one deal breaker on a date is to mention an ex. I have heard it time and time again that the reason a gal did not want to go back out with a guy is because he used his ex-girlfriends’ name in the conversation. Dating Tips for Men 101, never mention an ex. Again, it should go without saying but I guess some people missed out on the basic information about first dates.