Telling people to "kys" needs to stop

I recently played a match where I was AD Kennen in the jungle just to try it out. It was going okay until my grandparents came over to greet my family; I quickly told my team that I would be gone for 5 min more or less because my grandparents were here. Anyways, I came back after 10 min, apologized for being gone for so long, and I promptly witnessed our top laner telling me to "kys and your grandparents". This behavior needs to stop; people seem to think that it is a light humor but to people who have lost close ones from suicide it is incredibly infuriating and depressing. Maybe that reaction is just my experience but my point still stands that you should not be telling people to kys.

tl;dr don't tell people to kys