The ignorant elderly?

Okay so I manage a gas station on a busy street in my city.. I have worked here for almost 5 years. So my customers have seen me through my first pregnancy with my son as well as so far with my daughter. I get the usual 'congrats' 'OMG a girl! Yay!' But this past Friday I got what I've not been looking forward too. I had an older man (who used to be a regular before his health took a plunge) and he came in and looked at me and said 'you've got to be kidding me'. 😑 so I simply said 'what'. And he came back with 'are you crazy? Or stupid?' And I said 'if your referring to my pregnancy it's clearly a decision I made and honestly I don't care about your opinion.' And the proceeded to ask if I'm married. Well no but I'm with my children's father that they both share. I'm perfectly happy with my little family and it's overly frustrating when I'm already working long days dealing with people of all kinds as is I can't stand when people can't just keep their opinion to themselves. 
Not to mention I'm 22 weeks and just popped so I've been getting a crazy range of comments. This one just TOPPED my day.