my ex passed away, am i allowed to be upset?

my daughter's dad passed away a couple days ago & i was with my current partner and his family when i got the news. i was quite distraught but i felt like i wasn't allowed to be upset whilst surrounded by them, so i excused myself & went home.

is it wrong of me to be upset? my mil makes me feel like im somehow cheating on her son bc im crying over another man..