That's honestly a terrible way to greet someone, bro :

Depending on how cool OP was with their friend, it's not too out of place to joke around during a greeting. It just so happened that OP accidentally made the joke at the wrong time

My friends say it to me all the time because I'm always absent. I can see how OP would too if they're close friends. Just bad timing.

An honest mistake. How would you know? Don't worry OP, I'm sure he didn't find it offensive.

I think it was a little to early for his friend, it might not be so offensive but it can be a very emotional topic to be touched and given it happened recently means the wound would still be raw. Unlucky op maybe you can take him out for some lunch or something to help him cheer up.

This is not even a good FML. Why does this get published?

Yea this one is pretty fucking awful to be honest.

Ouch. It happens, OP. I know you didn't mean any harm by the comment, and you couldn't have known. Try not to beat yourself up about it.

Friends greet themselves in different ways all the time. This is in no way OP's fault. Just unfortunate timing.

Well I can't exactly blame you, but maybe next time just be a bit safer with how you greet a mate after their absence. I offer my condolences to your friend for the loss of his grandmother.

If someone's missing from school it's usually safe to assume there's a reason. Maybe next time you'll know to find out that reason before making jokes that could make you out to look like an asshole.

People may skip or take vacations though

Or he could have been sick, like OP assumed, because he HAD been recently sick...

Honestly op, if I was that guy I would've started laughing.

Body language would have helped in this situation, your friend would probably have seemed more down than if he were to be sick, sorry about his grandma

Hopefully if he's a good enough friend to forgive you. Otherwise sorry for you cause of how bad a slip up that was. Also for your friend for losing someone