If you have a relationship where you tease each other, then perhaps he didn't realise his comment would hit a mark...
My DH has, in the past, started to tease me about something which he didn't have any strong feelings about but which he thought would be funny, without realising that he'd picked something I was sensitive about.
For example, like many women, I have a facial hair problem, which I was extensively bullied about at school. As a result, I was very careful to keep on top of it and in the early days of our relationship he had no idea.
Until the day he decided it would be funny to pretend he could see my mustache.
I didn't have a mustache at the time, but only because I waxed! DH didn't know women could actually grow facial hair and thought we only ever got fluff, and thought calling fluff an actual mustache was so ridiculous that I would obviously know he was joking and didn't mean it.
I didn't realise he was joking at first and was mortified - I was in floods of tears, hiding under the duvet, telling him to fuck off out of the room so I could get my waxing kit out in private and sort it out, although I didn't tell him that - just shouted "Just fuck off!" through my tears from under the covers.
He was baffled by my extreme over-reaction...