Starting maternity leave

I was looking forward to not having to go to work anymore. It is a luxury, having paid maternity leave and I'm ready to embrace it. Since I work on an IT department with mostly guys (95% or so, although my little team is much better with only 81%) this is a rare occurence and not everyone is aware of it. So I wanted to share some cake on my last day, celebrate this milestone, and say goodbye for four months. (and felt very brave, ordering cakes with a baby theme!)

At the end of 20 minutes there were still some cakes left, so I trundled over to the department where HB and DP work.
HB was at his desk and had a cake. The guy sitting opposite him, who has seen me visiting almost every day looked at the cakes I offered, looked at me again and asked me: " but why are you going on maternity leave? "
Uhm, because I'm pregnant? -me patting the basketball under my jumper
"but, how long? "
a good 8 months, baby due in February.
"But, my wife is due in February as well! Congratulations!"

I'm still amazed at his lack of radar. I know it is very possible that his wife has a bigger belly as it is their second, and I carry relatively small since I'm so tall and Grasshopper is vertical.
But still.....Hello.?!?!