Passed on people's birthdays?

So my boyfriend and I were speaking about my parents age and his father passed away and I asked what his parents ages were and he told me I know his father is dead and I asked well what was his age going to be and he said his not talking about it and got upset, I just asked cause even though my sister passed away we still sort of celebrate her birthday and memory so I didn't think it would be a big deal, thoughts? I don't know what to say to fix it
Passed on people's birthdays?
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