Cancer.

I know it may seem a bit soon posting but I don’t know what to do I’ve never done this before, this afternoon my mother in law passed of cancer age 41 my SO rang me with the bad news while I was looking after his 11 year old brother, my SO is 23 he was crying on the phone, now he has come back home and he seems ok he is laughing and joking around with me and his brother and I just feel a tad awkward because if that just happened to me I would be crying none stop but obviously this is the way he is coping can anyone just tell me if the way he is being is ok and should I just be normal with him? again just to note I know all people grieve differently no hurtful replies please, thank you.