Aunt she planned a surprise birthday party for my mom and didn't let me know text me call or say anything

Would you be pissed off or not give a shit?

I think it's deceitful behavior

She threw my mom a party with strangers people she doesn't know

My mom came home stressed and vent to me about it

If my aunt would have talked to me about it I would have helped her with everything I feel like she did this behind my back so she can say she did something for my mom I'm mad I'm her daughter my mom has sons and a husband and instead of the family singing happy birthday it's with strangers that's like if I do a birthday party with our family and friends and exclude her and when she comes home she finds out we did everything and didn't mention shit to her like oh it's not a big deal

Idk how to feel